How to check CEL on 1st gen?

[CobraSpdRH]

Hey guys I just picked up a 95 SOHC 2 door today for my daily while the SRT is undergoing some "renovation" ;) . The car runs great and I'll probably just give it a basic tune up this weekend but it just threw a CEL on me this afternoon after a drive on the interstate and I'm not sure how to get the CEL # or where to reference the #. I looked around a little on Floridaneons.org but I'm kinda new on there and couldn't find it. Any help would be much appreciated. Also, once I fix the code how do you reset the ECU?

Thanks for the help

Rob

[neondriver]

its easy but i cant remember right now i have the list at home, all you do is turn the key on-off-on-off-on then the engine light blinks in a pattern corresponding to a code.

check neons.org or allpar.com

and to reset the ecu....dissconnect the battery for a while

[neondriver]

actually here it is

1ST GEN 1994 TO 1999

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 - it's normal. Before you call your dealer or mechanic, consider that the blink-spacing is not always perfectly uniform, so if you see 23 23, it's probably just a single 55. (Codes are not repeated.)
33 is normal on earlier models if you don't have air conditioning.
John McGuire wrote: "The older Vipers will blink out diag codes with four off/on key turns. They removed the capability starting in... I think 2000, at any rate I know my 2001 requires a computer to check the codes."
On some models (such as a 1995 Neon), when the check engine light goes on, you may be able to get the codes simply by putting in the key and moving it to the RUN position; the light will blink out the codes by itself.
Please note that some codes are NOT included below, this is not a complete listing, but it IS very close to complete. It stemps from a list posted on the Mopar Mailing List, but many modifications have been made.
* Activates Power Limited/Check Engine light on some models.
IMPORTANT. Codes may be different for newer vehicles starting in the late 1990s. See the earlier section.

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. Can cause the engine to stop working entirely with no limp-home mode.
12 Battery or computer recently disconnected
13* MAP sensor or vacuum line may not be working
14* MAP sensor voltage below .16V or over 4.96V
15 No speed/distance sensor signal
16* Loss of battery voltage detected with engine running
17 Engine stays cool too long (bad thermostat or coolant sensor?)
17 (1985 turbo only): knock sensor circuit

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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


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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 temperature sensor voltage low (1995 and on; see NOTE 2)


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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


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51 Oxygen sensor stuck at lean position (Bob Lincoln wrote: may be tripped by a bad MAP sensor system causing a rich condition, and the O2 sensor trying to compensate. The O2 sensor may still be good. The MAP assembly consists of two pieces, the valve and the vacuum transducer (round plastic unit with cylinder on top and both electrical and vacuum connections) - If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold driveability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. [Webmaster note: MAP sensors seem to die regularly.]
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) - or camshaft sensor/distributor timing (7)
55 End of codes


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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


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88 Start of test (not usually given, don't expect it)
Footnotes


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.


Note #7Steve Knickerbocker wrote: Inside your distributor you have two pickups, one is for the ignition and one is to tell the computer where number one cylinder is in its rotation. If you look at the four slotted tangs inside there you will see one has a bigger slot, that's the one that tells the sync pickup what's number one. In other words, the pickup inside the distributor is bad.

[CobraSpdRH]

Cool thanks man...the "three turn" thing is the same on the SRT's it just reads it out on the digital dash rather than the blinks of the CEL light. I went out to my car to get the code and nothing came up, started the car and no CEL, I guess it cleared itself. I know the battery was pretty low on its charge b/c the car had been sitting for awhile maybe that was it. Thanks again for the help.

I'll probably be hittin you 1st gen guys up for some more info. here to come, I have to change the o-rings on the expansion valve to get the ac workin again, anybody had to deal with that?

[SlowAssNeon]

btw, i prefer to reset the pcm by pulling the fuel pump fuse rather than disconnecting the battery. dont lose any radio presets that way, and no tools needed to do so.

kinda odd that you checked for codes and nothing was there. low battery voltage shouldnt really give a code.. im thinking it was either downstream o2 sensor code, or EGR myself since it tripped during freeway driving.

[CobraSpdRH]

kinda odd that you checked for codes and nothing was there. low battery voltage shouldnt really give a code.. im thinking it was either downstream o2 sensor code, or EGR myself since it tripped during freeway driving.

Yeah well it threw a battery light on the drive home from where I bought it which was no biggie to me b/c I figured it would charge up on the ride home. Then once I got it home I started it and got the CEL. I let it be and when I came back to check it was gone. I didn't figure it was anything big which is why I wanted to make sure to know how to reset the PCM. So far the car has had its fair share of similarities to my SRT (except the power of course) which works out in my favor as I'm pretty familiar with that by now.

Rob

[bOoStIn-NeOn]

Finally got a beater car huh??

[CobraSpdRH]

Oh yeah, it's great to have a spare car and this one is suprisingly reliable, I'm impressed