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Archive-name: autos/chrysler-faq/general/part3
Posting-Frequency: 15 days Last-modified: 2004/4/13 Version: 4.5 See reader questions & answers on this topic! - Help others by sharing your knowledge Modifications and detailed fixes are at the web site - http://www.allpar.com/ IMPORTANT. Do not attempt to respond to faq@allpar.com. Due to spam this address DOES NOT GO ANYWHERE. Instead, reply to faq2 at that allpar /dot/ com address. Thank you. - - - - - - - - - - - - See the very last part of this section for reading ESA computer codes without a scan tool! Useful for those without the key-turn-watch-light feature (e.g. 1985 Caravans) -- and those with it! Note that engine codes have been updated since this list was created. See http://www.allpar.com/fix/codes.html for an updated list. Contents: 1. Engine Codes 2. [Outdated and removed] 3. Classic Car Troubleshooting 4. Reading codes without a scan tool (computer controlled, carbureted engines) 5. Crankcase inlet air filter, 2.2/2.5 engines. DISCLAIMER: While effort has been taken to insure the accuracy of the information contained in this FAQ list compilation, the author and contributors assume no responsibility for errors or omissions, or for damages resulting from the use of the information. The information may be reproduced IF credit is given to the writers and the maintainer; and that it is not published without the prior written permission of the maintainer; that the maintainer receives, without needing to ask, a free copy of the final material; and that no changes are made without the express permission of the maintainer (David Zatz who is at http://www.allpar.com/). - - - - - - - - - - - - The latest copy may be obtained from http://www.allpar.com/faq.html - - - - - - - - - - - - FAQ for rec.autos.makers.Chrysler - Part III ******************************************************** COMPUTER CODES THESE ONLY WORK IF YOU HAVE FUEL INJECTION. Otherwise, see the web site or the "troubleshooting electronic feedback carburetors" section. Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. (On is *not* start!) The "check engine" light will flash. Count the flashes Each code is a two digit code, so a (for example) 23 would be FLASH FLASH <pause> FLASH FLASH FLASH <loong pause> It will never flash more than 9 times, watch for pauses! 55 is end of codes, 33 is normal if you don't have air conditioning. When the computer indicates major failure, it will activate Limp In mode, which guesses about data to compensate for sensor failure. *** NOTE - NEWER VEHICLES *** See http://www.ptcruizer.com/computer-codes.html for a new, revised list of computer codes and instructions on how to get them. These codes appear to have been phased in starting in around 1998. *** Please note that some codes are NOT included below, this is not a complete listing. (From Herb with additions by Charles Hobbs. Basis: Mopar Mailing List info.) * Activates Power Limited/Check Engine light. 11 No ignition reference signal detected during cranking (bad Hall effect) OR timing belt skipped one or more teeth; OR loss of either camshaft or crankshaft position sensor 12 Battery or computer recently disconnected - Fraser Shortt said code 12 appeared with some other codes in 1989 and possibly later computers as well. 13* MAP sensor or vacuum line may not be working 14* MAP sensor voltage below .16V or over 4.96V NOTE - on early Neons, a computer error may light the Check Engine light and show one or more of these codes. If this happens, bring it in so the dealer can reprogram the computer (about ten minutes). 15 No speed/distance sensor signal 16* Loss of battery voltage detected with engine running 17 (1985 turbo only): knock sensor circuit 17 Engine stays cool too long (bad thermostat or coolant sensor?) 21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V) Probably bad oxygen sensor 22* Coolant sensor signal out of range - May have been disconnected to set timing 23* Incoming air temperature sensor may be bad 24* Throttle position sensor over 4.96V (SEE NOTE #3) 25 Automatic Idle Speed (AIS) motor driver circuit shorted or target idle not reached, vacuum leak found 26 Peak injector circuit voltage has not been reached (need to check computer signals, voltage reg, injectors) (SEE NOTE #4 BELOW) 27 Injector circuit isn't switching when it's told to (TBI) OR (MPI) injector circuit #1 not switching right OR (turbo) injector circuit #2 not switching right OR (all 1990-) injector output driver not responding - check computer, connections 31 Bad evaporator purge solenoid circuit or driver 32 (1984 only) power loss/limited lamp or circuit 32 EGR gases not working (1988) - check vacuum, valve 32 (1990-92, all but Turbo) computer didn't see change in air/'fuel ratio when EGR activated - check valve, vacuum lines, and EGR electrical 33 Air conditioning clutch relay circuit open or shorted (may be in the wide-open-throttle cutoff circuit) 34 (1984-86) EGR solenoid circuit shorted or open 34 (1987-1991) speed control shorted or open 35 Cooling fan relay circuit open or shorted 35 (trucks) idle switch motor fault - check connections 36 (turbo) Wastegate control circuit open or shorted 36 (3.9/5.2 RWD) solenoid coil circuit (air switching) 36 (Turbo IV) #3 Vent Solenoid open/short 37 Shift indicator light failure, 5-speed OR part throttle lock/unlock solenoid driver circuit (87-89) OR solenoid coil circuit (85-89 Turbo I-IV) OR Trans temparature sensor voltage low (1995 and on; see NOTE 2) 41* Alternator field control circuit open or shorted 42 Automatic shutdown relay circuit open or shorted 42 Fuel pump relay control circuit 42 Fuel level unit - no change over miles OR 42 Z1 voltage missing when autoshutdown circuit energized (SEE NOTE #6) 43 Peak primary coil current not achieved with max dwell time OR 43 Cylinder misfire OR 43 Problem in power module to logic module interface 44 No FJ2 voltage present at logic board OR 44 Logic module self-diagnostics indicate problem OR 44 Battery temperature out of range (see Note #1!) 45 Turbo boost limit exceeded (engine was shut down by logic module) 46* Battery voltage too high during charging or charging system voltage too low 47 Battery voltage too low and alternator output too low 51 Oxygen sensor stuck at lean position (lean condition) OR 51 Internal logic module fault ('84 turbo only) 52 Oxygen sensor stuck at rich position (SEE NOTE #5!) OR 52 Internal logic module fault ('84 turbo only) 53 Logic module internal problem 54 No sync pickup signal during engine rotation (turbo only) OR 54 Internal logic module fault ('84 turbo only) 55 End of codes 61 "Baro" sensor open or shorted 62 EMR mileage cannot be stored in EEPROM 62 PCM failure SRI mile not stored 63 Controller cannot write to EEPROM 64 Catalytic converter efficiency failure 65 Power steering switch failure 88 Start of test (not given on most computers) NOTE #1. The power module has an air-cooled resistor which senses incoming air temperature. The logic modules uses this information to control the field current in the alternator. This code applies ONLY to alternators whose voltage is computer regulated. If you lose the feed to keep RAM information stored when the engine's off, you also lose battery voltage sensing. -- Bohdan Bodnar NOTE #2 From the 1995 TRUCK manuals: the trailer towing package includes a transmission coolant temp sensor while the standard package doesn't. This may cause the low (no) voltage indication. -- J.E. Winburn NOTE #3 Matt Rowe comments: The throttle postion circuit tells the computer how far the accelerator is depressed. The Throttle Position Sensor (TPS) is on the throttle body on the opposite side of the throttle cable. The connector should have a round rubber cover over the connections. Clear the fault codes, start the car and try jiggling the wires/connectors to try to trip a fault code. Loss of this signal could cause other problems. NOTE #4 During cranking, the computer will test the current through the injector to see whether there's too much resistance in the injector's path. If there is, code 26 is set. The problem may be cured with tuner cleaner on the connectors. For TBI engines, the injector's cold resistance should be between 0.9 and 1.2 ohms (specs vary with year). This is a peak-and-hold injector. With the engine idling the peak period should be about 1.2 milliseconds whereas the hold period will vary. If it's lower than this at idle, then the injector's shorted or there's a defect in the injector driver circuit. (Bohdan Bodnar) NOTE #5 Wade Goldman wrote: In my case, the breather tube leading into the catalytic converter had rusted and become detached. This some how would cause the sensor to read an over rich condition and run crummy. I did not trust the reliability of the weld over a corroded surface and opted for the more expensive route of replacing the converter, breather tube and all. NOTE #6 The Z1 voltage is the voltage of the circuits fed by the autoshutdown relay. This typically includes fuel pump and switched-battery feed to the ignition coil(s). In my Le Baron, the Z1 circuit leaves the power module and splits into two paths: the fuel pump and the positive side of the ignition coil. Internal to the power module is the auto shutdown relay (in my case, it's a sealed box about 1" by 1"). The output voltage is monitored to determine whether the relay responds correctly. I suspect that the ASD relay (and, therefore, the Z1 circuit) also feeds the fuel injector(s) driver(s) and current sensing circuit, but can't prove this. I've used the Z1 voltage to test for good power connections to the power module. I connected my OTC 500 multimeter from the battery's positive post to the ignition coil's switched battery terminal and measured the voltage drop using the bar graph to monitor peak voltages. Voltage spikes of around 200 mV to 300 mV are ok -- anything more means tv tuner cleaner time (or replacing the power module). Another thing to check is the maximum voltage drop during the priming pulse. With the old power module, I was losing about 2 volts across the circuit; the replacement is losing about 1/4 volt. (Thanks, Bohdan Bodnar) **************** CLASSIC CAR TROUBLESHOOTING **************** (1950s-some 80s) FOR MORE, VISIT http://www.allpar.com/fix/vintage.html Many of these were taken from the A-Bodies site at http://www.valiant.org/ C1. Won't start (<Dave>): Check the ballast resistor. It's a little white block attached to the metal between the engine and the driver, with a single bolt; wires plug into each side. It's easy to replace and under $5. If the starter makes a rapid clicking noise, your battery may be worn, even if you can see your headlights. If the engine was wet, dry it, separate the wires, and try again, Use silicone spray or "wire drier" or, better yet, replace your wires with really good ones ($25-40 mail order). These will probably improve your gas mileage and power as well. Dan Stern adds: Whitaker's Multi-Mag comes in the same colors and insulation materials as original, but uses the spiral-wound construction that you find in wires such as Accel and Jacobs. Lower resistance, but no irritating radio noise. They have a lifetime guarantee and don't cost more than regular carbon-string type wires. The Slant-6 wire set (32605 for pre-75) has the correct 1-piece moulded plug boots. They are also sold under the Borg Warner/BWD KoolWire name. ----------------------------------------------------------------------- C2. Anything from pollution to loss of power (<Dave>) This may be caused by leaking vacuum hoses or mechanics disconnecting your vacuum hoses. If you like to breathe, and you want your car to perform well, replace all of the vacuum hose -- it costs maybe 10 cents per foot. Just get a few yards and do it one day (warning: you may need different kinds or sizes. You may need to take bits of the old stuff into the shop). Make sure hoses are not kinked. Vacuum leaks caused by leaking hoses that look okay to the naked eye may result in the following diagnoses by mechanics: * Need new carburetor * Need new transmission * Need new engine * Need valve job * Need new mechanic. ----------------------------------------------------------------------- C3. Stalling (<Dave>) See the above section on vacuum hoses. Turning the cold or warm idle screw on the carburetor is a quick fix that doesn't solve the real problem. If the car stalls when cold, lubricate the choke well. If it stalls when wet, try getting much better ignition wires (lifetime warranty, good brand, about $30). Also try: * Put window insulating tape (foam) over the top of the electronic ignition module * Spray the little wires with silicone spray or wire drier * Check for vacuum leaks (see above). ----------------------------------------------------------------------- C4. Windshield wipers won't work (): Put window insulating tape (foam) over the top of the wiper motor. ----------------------------------------------------------------------- C5. Water leaks into the car: A problem on many A-bodies (Valiant/Dart group). May be solved by keeping the cowl (that grille between the hood and windshield) free of leaves and gunk, and by straightening out and emptying out the air conditioner condensation drain. The black tube that carries a/c water may be seen on the firewall (the metal between the engine and the driver). It is small and behind other stuff. Sometimes the end of this black tube freezes to itself and must be opened with a knife or razor. See http://www.allpar.com/a/water.html ----------------------------------------------------------------------- C6. runs rough cold, seems to improve with heat George Young suggests: 1) Not enough voltage from old damp coil? - new coil. 2) EGR valve plunger binding open? - remove and plug manifold vacuum hose to EGR circuit. Dave adds: Better wires, high quality rotor/distributor cap for best fit. Check the stove, that big metal thing on many engines that feeds warm air from the engine to the air intake through a usually-rotten or missing hose. The vacuum-operated flap may also not be functioning for one reason or another, usually a bad vacuum hose. This is common. Dan Stern notes the flap is controlled by the Thermostatic Air Cleaner vacuum motor... George Young adds: My old 318 ran rough when cold and wet, would stall out until warm. Choke was the problem. Manifold carboned up and wouldn't pass heat to choke coil thermostat. Changed to manual choke and no more problem and increased gas mileage Dan Stern noted that driveability problems could be caused by a bad choke heater control unit, which may short out and shunt full power to the electric choke, causing it to heat up prematurely. ----------------------------------------------------------------------- C7. Lean-Burn (computer-controlled carbureted engine) rough idle 1). Are your coolant temperature sensor connection ok? If not, the computer will see a cold engine and will run rich. 2). Are the oxygen sensor connections ok? 3). Is the heated air inlet operating correctly? 4). Vacuum leaks? Check all vacuum hoses with a religious fervor! The leak's location many not even be obvious! 5). Carburetor problems: float low? valve seat damage? I doubt the latter since it appears that the problem arose quite suddenly. The following is something I've used on computer-controlled carbureted engines many times: 1). Connect a high impedance dwell meter to the mixture control solenoid, set the meter to the 6 cylinders scale, run the engine around 2000 rpm until hot and see the dwell. If the a/f mixture's ok, you'll see the dwell oscillating about 30 degrees. Low dwell with oscillations => a/f mixture lean and running closed loop. High dwell with oscillations => a/f mixture rich and running closed loop. Dwell at or below 10 degrees => system stuck lean. Dwell at or above 50 degrees => system stuck rich. The latter two extremes indicate closed loop operation since open loop operation typical will show a stable dwell reading between 20 and 30 degrees (usually, closer to 20). Do not do this test at idle since some engines will be operated in open loop at idle REGARDLESS of the coolant temperature sensor's output. Incidently, I've just outlined the procedure for GM's "System Performance Test" which is used on GM C3 carbureted engines. ----------------------------------------------------------------------- C8. Gas gauge acts funny: See #34. (part 4) ----------------------------------------------------------------------- C9. Stalling or poor idle - wet weather / snow -- see #39 (part 4) ----------------------------------------------------------------------- C10. Slant Six problems Cold driveability problems tend to stem from poorly adjusted choke and choke pulloff, bad accelerator pump, and sloppy carb rebuilds (Carter BBS one barrel is better than Holley 1920.) Other big driveability problem source is the fact that the vibration damper outer ring tends to slip, which makes the timing mark WAY OFF. Which means timing would never be accurately set. Also check for timing chain stretch. Check by putting the engine at #1 TDC - top of compression stroke (both valves closed) and see where the timing mark is. There are companies that re-bond dampers with new silicone material. I think one is called Damper Dudes, out of California. I don't know if this happens on other CC engines. Basically, if your damper has an inner hub and an outer ring sandwiching rubber bonding material, this can happen. ----------------------------------------------------------------------- C11. 318 V8 troubleshooting Bruce Martin wrote: One very common fault with the otherwise wonderful 318 is that the exhaust crossover in the intake manifold (which warms the base of the carb) becomes clogged. This is common so it should be among the first things you check. (This problem was addressed on the Magnum engines) CURT PINCK wrote: It is interesting the wide variety of timing specs given for the 318, all the way from 2 degrees ATDC to 16 degrees ATDC, depending on the type of engine and vehicle...Most books recommend not to try to time by ear, even if you have experience doing this. Ted Devey adds two more steps: 1. examine the reluctor teeth in the distributor for possible damage, nicks etc. which can happen if the gap gets too small. If there is damage to the teeth, replace the reluctor. 2. Several years ago I dismantled the Carter 2-barrel carburettor and reassembled it with the jet assembly upside down. There is no obvious wrong way. ----------------------------------------------------------------------- C13. Seat belt looseness During the late 70's up through the late 80's all American cars had something called a window shade mechanism to allow for a small amount of slack to build-up in the shoulder belt. This was to prevent people from complaining that their belts were too tight. I experienced (ref:June '87 Car and Driver article by Patrick Bedard) a problem where the seatbelt built up too much slack. Sometimes the belts, like a windowshade, would never return at all. There is usually a large plastic button on the 'B' pillar that needs to be fooled into thinking the door is always opened, which by the way disables the window shade mechanism and is how the belts return 'home' when you get out of the car. Cut the plastic button very close to the 'B' pillar, being careful not to cut into the inner spring Take a cotter pin and put it through the loops of the spring, this prevents the spring from ever retracting. Chrylser mini-vans are easier in that they have a rotating plastic cam with a striker pin that is engaged by the closing door. Just cut the striker pin and you eliminate the problem. ----------------------------------------------------------------------- C14. Low front end Many late 60's and early 70's A-body Chrysler products had a problem with the rear mount for the torsion bar. Water collects in the channel and rust occurs. After a decade or so the channel that the mount is welded into rusts through and the mount twists and that side of the car falls onto the rebounce (sp?) bumper. If this is what happened you will need to find a local frame/suspension/alignment shop that has someone who has welded in new material to replace the rusted stuff and then realign the ride height when done. (Thanks, Chris Jardine). ----------------------------------------------------------------------- C15. Pinging on V-8s Pete O Dickerson wrote: My 75 Dodge Swinger 318 would ping at part throttle operation, not at full throttle (floored!) like you might expect. Just going over an overpass or up a hill the engine would ping and clatter, even though the ignition timing and carburetor were set correctly. The manifold was made from cast metal. The molten metal was poured into a mold through a little hole and when the manifold was finished, the little hole was plugged up with a little rubber plug. Well, after a few years this little plug would dry up, shrink, and fall out, leaving a hole in the manifold. This hole would cause a lean condition to exist at part throttle operation, by letting air leak in. Try removing the carb and shining a flashlight down into the manifold and seeing if there is a hole in the bottom of the manifold. You can either plug it up or replace the manifold with a more performance oriented unit. (The maintainer adds: invest in a vacuum gauge, they are cheap!) ----------------------------------------------------------------------- C16: Fast idle, then stalling. >From Timothy Economou: If you start your car and it runs for a while at fast idle and then it starts to load up and then stalls. There is this little round thing on the open end of your breather that closes the outside air when your car is at fast idle and lets it draw air from the manifold. (Stove control). Check it. Editor's note: the stove control is frequently bad on vintage vehicles. The vacuum hose, control, and mechanics of the flap in the air horn should be checked. See above. ----------------------------------------------------------------------- ========================= DIAGNOSING PROBLEMS IN COMPUTER CONTROLLED CARBURETED ENGINES From: Bohdan L Bodnar This is the procedure I've used to diagnose air/fuel mixture problems in computer controlled carbureted engines; the procedure can also be used to set the idle air/fuel mixture without exhaust gas analysis. The procedure is based on the General Motors System Performance Test. THEORY The a/f mixture is controlled by a MIXTURE CONTROL SOLENOID (MC solenoid). This is a valve which operates at a fixed frequency (typically, 10 Hz) and whose duty cycle (valve's ON time divided by period) is varied. That is, the valve is pulse width modulated. When the valve is turned on, the incoming a/f mixture is fully leaned; when off, fully enrichened. The former is called a "lean command" whereas the latter is called a "rich command." By varying the duty cycle of the MC solenoid, the AVERAGE a/f mixture can be varied. In GM products, this valve directly varies the incoming fuel and air flow. In Chryslers, only the incoming fuel flow is directly varied. The valve has a two wires electrical connector. On wire is connected to switched battery voltage whereas the other is connected to a power transistor in the computer and is a source of switched ground. During closed-loop operation the following will occur (assume the oxygen sensor is sensing a lean condition -- its voltage will be low): 1). The computer gradually decreases the MC solenoid's duty cycle. 2). The exhaust eventually becomes rich enough that the oxygen sensor's output will swing high (about 1 volt). 3). The computer gradually increases the MC solenoid's duty cycle. 4). The exhaust eventually becomes lean enough that the oxygen sensor's output will swing low (about 0 volt). The cycle now repeats. A device for monitoring the solenoid's duty cycle (such as a dwell meter) will show a constantly varying duty cycle. The frequency of the oscillations will depend on the how fast the computer varies the duty cycle and the engine's RPM. An AVERAGE duty cycle of 50% corresponds to, on the average, NO average a/f correction. Stated differently, everything is operating correctly. An average duty cycle of LESS THAN 50% corresponds to, on the average, a rich command (the computer is compensating for a lean condition). An average duty cycle GREATER THAN 50% corresponds to, on the average, a lean command. DIAGNOSIS AND SETTING IDLE A/F MIXTURE Monitoring the MC solenoid's average duty requires (for most people) the use of high impedance dwell meter. A low impedance dwell meter may be used unless it affects engine operation; stay away from self-powered dwell meters. Following the GM procedure, set the dwell meter to the six cylinders scale REGARDLESS of the number of cylinders in the engine. At this setting, 30 degrees will correspond to a 50% duty cycle, 60 to a 100% duty cycle, and 0 to a 0% duty cycle. Run the engine until closed loop operation is present; this will be indicated by a varying dwell (see footnote 1 for deviations from this procedure). Once the engine is hot, not the average dwell -- the reading should vary equally above 30 degrees and equally below 30 degrees. The following is a brief trouble listing: 1). DWELL NOT VARYING: system is operating in open loop. 2). DWELL STUCK AT 10 DEGREES OR LOWER: full rich command is present; the computer is compensating for WHAT APPEARS TO BE a massive fuel flow reduction (check for dirt in carburetor, air injection system stuck in upstream position, vacuum leaks, improper a/f mixture setting...). 3). DWELL STUCK AT 50 DEGREES OR UP: full lean command is present (check for float stuck low, valve seat damage, oxygen sensor's sense lead shorted to battery voltage, etc.) 4). DWELL OSCILLATING, AVERAGE READING IS BELOW 30 DEGREES: average rich command is present (check for vacuum leaks, dirt in carburetor's jets, improperly set a/f mixture...) 5). DWELL OSCILLATING, AVERAGE READING IS ABOVE 30 DEGREES: average lean command is present. Check for incorrectly set a/f mixture, float stuck low, valve seat damage, clogged air filter, etc...). Based on the above descriptions, it should be fairly clear on how to set the idle a/f mixture: merely set the mixture so that the average dwell is 30 degrees. Now, suppose the system's dwell is not varying, but the sensors are working properly, the upper radiator hose is hot... Several cars with small engines have the oxygen sensor mounted fairly far away from the engines. During idle conditions, the sensor may cool off to the point that it will not operate. Turn off all electrical accessories (so as to provide a minimal load on the engine) and use the idle stop screw on the carburetor to gradually increase the idle rpm until the sensor begins oscillating. Ensuring a negligible load on the engine guarantees that the carburetor will be operating mostly on its idle circuit. Now, set the a/f mixture so that the average dwell is 30 degrees. Note that the a/f mixture setting procedure assumes that NO fuel delivery problems (vacuum leaks, clogged carburetor, etc.) are present. FOOTNOTES [1] In some engines the a/f mixture is varied REGARDLESS of whether the engine is in closed loop operation or not. Consider setting the a/f mixture or diagnosing at a slightly increased rpm. ************************************************** 5. REPLACING CRANKCASE INLET AIR FILTERS If you remove the air cleaner and look at it from the front, the breather (crankcase filter) will be in the "box" at the lower right side. To get at it, you remove the 8 or so machine screws and the bottom of this "box" will fall off. The filter is held in place by a crudely placed screen. Lee makes a replacement filter (about $2). In my Le Baron, I ended up replacing all the screws with self-tapping sheet metal screws since the factory had almost every one overtightened. --- Bohdan Bodnar David Zatz works at http://www.toolpack.com/ User Contributions: |
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