ALDL Fault Codes

[Dynomite]

Assembly Line Diagnostic Link (ALDL) Fault Codes

1. ZR1 ECM CODES 1990 TO 1992
Code #12: Normal No Codes.
Code #13: Left Oxygen Sensor Circuit.
Code #14: Coolant Temperature Sensor Circuit High.
Code #15: Coolant Temperature Sensor Circuit Low.
Code #16: Direct Ignition System (DIS) Fault Line Circuit
Code #21: Throttle Position Sensor Circuit High.
Code #22: Throttle Position Sensor Circuit Low.
Code #23: Manifold Air Temperature Sensor Circuit Low.
Code #24: Vehicle Speed Sensor Circuit.
Code #25: Manifold Air Temperature Sensor Circuit High.
Code #31: Camshaft Sensor Circuit.
Code #33: Manifold Absolute Pressure Sensor Circuit High - Low Vacuum.
Code #34: Manifold Absolute Pressure Sensor Circuit Low - High Vacuum.
Code #36: Direct Ignition System (DIS) Circuit (missing or extra EST signal)
Code #41: Cylinder Select Error (Faulty or Incorrect Mem-Cal)
Code #42: Electronic Spark Timing (EST) Circuit.
Code# 43: Electronic Spark Control (ESC) Circuit.
Code #44: Left Oxygen Sensor Circuit Lean.
Code #45: Left Oxygen Sensor Circuit Rich.
Code #46: Vehicle Anti-Theft System (VATS)(PASS-Key) Circuit.
Code #51: Mem-Cal Error.
Code #52: Engine Oil Temperature Sensor Circuit Low.
Code #53: System Voltage.
Code #54: Fuel Pump Circuit (Low Voltage)
Code #55: System Voltage
Code #56: Vacuum Sensor Circuit.
Code #61: Secondary Port Throttle Valve System.
Code #62: Engine Oil Temperature Sensor Circuit High.
Code #63: Right Oxygen Sensor Circuit Open.
Code #64: Right Oxygen Sensor Circuit Lean.
Code #65: Right Oxygen Sensor Circuit Rich
Code #66: Power fault for the valet switch.

2. ECM Related Explanations.
31 LCD Data Circuit-Circuit shorted to battery voltage or CCM driver open
33 Data Clock Circuit-Circuit shorted to battery voltage or CCM driver open
35 Data Strobe Circuit-Circuit shorted to battery voltage or CCM driver open
37 M Clock Circuit-Circuit shorted to battery voltage or CCM driver open
72 LCD Dimming Open Circuit-Circuit open or shorted to ground (radio & Climate control)
H History code. May be intermittant.
Code 31, 33, 35 related to the circuit from the CCM to the Instrument panel LCD.
CCM 74 is also a lighting circuit problem.
CCM 41 is loss of communication with the ECM.

3. ZR1 ABS Code - Definition
1990 Service Manual:
(* = Requires Tech 1 Daignostic Tool)
12 - Diagnostic System Operational
21 - RF Wheel Speed Sensor Fault
22 - RF Toothed Wheel Frequency Error
25 - LF Wheel Speed Sensor Fault
26 - LF Toothed Wheel Frequency Error
31 - RR Wheel Speed Sensor Fault
32 - RR Toothed Wheel Frequency Error
35 - LR Wheel Speed Sensor Fault
36 - LR Toothed Wheel Frequency Error
41* - RF Solenoid Valve Fault
45* - LF Solenoid Valve Fault
55* - Rear Solenoid Valve Fault
61* - Pump Motor or Motor Relay Fault
63* - Solenoid Valve Relay Fault
71 - EBCM Fault
72 - Serial Data Link Fault
75 - Lateral Accelerometer Fault (Short to B+ or Ground, or Open Circuit)
76 - Lateral Accelerometer Fault (Signal Out of Range or Incorrect)
Clearing Codes
The fault codes in the EBCM's memory are erased in one of three ways:
1. Diagnostic Enable Line Procedure
2. Tech 1 "Clear Codes" Selection
3. Igniton Cycle Default
Whichever method is used, be sure to verify proper system operation and absence of codes when clearing procedure is completed.

4. ZR1 Ride Control (SRC) Codes.
12 = Start of sequence
13 = Left rear time out
14 = Right Front time out
21 = Left Front time out
22 = Right Rear time out
31 = Left Front out of position
32 = Right Front out of position
33 = Left Rear out of position
34 = Right Rear out of position
Out of position codes are triggered if the computer senses that the actuator has not found the end stop position on the shock. Remove actuator at the indicated shock. Turn the valve gear on the shock stops after about 3 / 4 of turn, then you have a bad actuator. If it spins around continuously then it is a bad shock
41 = Selective ride control switch short to voltage
42 = Selective ride control switch open contacts
You can have a code 42 if you leave the switch in between indented positions
43 = selective ride control switch circuit open.
23 = If you start the car more than 3 times and do not move the car this code will set. Drive 3-6 feet and the light will go out.
The ride control controller is located in the bin behind the drivers seat mounted with the ABS controller.

5. ZR-1 CCM Codes
Code Definition
1.1 DISPLAY CCM fault codes
12 On-board diagnostics no codes (this is a good thing: no problem found)
13 DIC switches open or shorted to battery
14 DIC switches shorted to ground
16 Ignition 3 fuse circuit open
21 Horn relay coil shorted to battery or CCM internal open circuit
22 Rear defogger relay coil shorted to battery or CCM internal open circuit
24 Courtesy lamp relay coil shorted to battery or CCM internal open circuit
25 Courtesy lamp relay coil circuit open or shorted to ground
26 LCD blanking control circuit shorted to battery or CCM internal open
27 LCD blanking control circuit open or shorted to ground
31 LCD data circuit shorted to battery or CCM internal open
32 LCD data circuit open or shorted to ground
33 Data clock circuit shorted to battery or CCM internal open circuit
34 Data clock circuit open or shorted to ground
35 Data strobe circuit shorted to battery or CCM internal open circuit
36 Data strobe circuit open or shorted to ground
37 M clock circuit shorted to battery or CCM internal open circuit
38 M clock circuit open or shorted to ground
41 Loss of ECM serial data communications
51 Pass-key invalid key detection
52 Pass-key key detection circuit shorted
53 Pass-key ? key detection circuit open or shorted to battery
54 FEDS fuel enable failure
61 Pass-key ? key #1 programming resistance out of range
62 Pass-key ? key #2 programming resistance out of range
63 Pass-key ? key #2 programming resistance low
71 LCD dimming output circuit shorted to battery or CCM internal open circuit
72 LCD dimming output circuit open or shorted to ground
73 LED display dimming output circuit shorted to battery or CCM internal open circuit
74 LED display dimming output circuit open or shorted to ground

6. 1990 SIR Codes
For 90-93 Cars jumper A to K on the ALDL and the INFL REST light will flash
1990 SIR Codes
14 Front Sensor #1 (LH); Short to Ground
15 Front Sensor #1 (LH); Open Circuit
16 Front Sensor #1 (LH); Sensor Fault
24 Front Sensor #1 (RH); Short to Ground
25 Front Sensor #1 (RH); Open Circuit
26 Front Sensor #1 (RH); Sensor Fault
31 Inflator Squib; Current leakage to Battery
32 Inflator Squib; Current shorted to battery voltage
33 Inflator Squib; Current leakage to ground
34 Inflator Squib; Current shorted to ground
35 Inflator Squib; Open circuit
36 Inflator Squib; Squib fault
41 Indicator lamp circuit; Shorted to battery or ground
42 Indicator lamp circuit; Open circuit
51 Diagnostic unit faulty
52 Firing sequence confirmation set
53 Firing current confirmation set
54 Squib current has flowed

7. 91 & 92 & 93 SIR Codes
21 Steering Column Resistance Too High
22 Steering Column Resistance Too Low
23 Steering Column Circuit Voltage Too High
24 Steering Column Circuit Voltage Too Low
25 Short to Battery in Steering Column
26 Open in Steering Column Circuit
31 Open 36 VLR to Deployment Loop
32 Grounded 36 VLR to Deployment Loop
33 Diode B Shorted in Wiring Harness
34 Open in Ignition 1 Feed to Deployment Loop
35 Discriminating Sensor Open
41 Deployment Loop Energy Reserve Voltage Fault
42 Deployment Loop Energy Reserve Voltage Fault
51 Accident Detected
52 EEPROM Accident Data Area Full
61 Force Low or â??INFL RESTâ? Warning Lamp Circuit
71 Internal DERM Fault

8. 94 & 95 SIR Codes
For 94-95 Cars, jumper Terminal 4 to 12 on the ALDL and enter the CCM diagnostics, or use a Tech1
14 Dual Pole Arming Sensor Disconnected
15 Passenger Initiator Circuit Resistance High
16 Passenger Initiator Circuit Resistance Low
17 Passenger Initiator Circuit Open
18 Discriminating Sensor Interconnect Open
19 Passenger Initiator Circuit Voltage High
21 Driver Initiator Circuit Resistance High
22 Driver Initiator Circuit Resistance Low
23 Driver Initiator Circuit Voltage High
24 Driver Initiator Circuit Voltage Low
25 Initiator Circuit Short to Ignition
26 Driver Initiator Circuit Open
28 Current Sink or Source Failure
31 Driver Loop Energy Reserve Feed Open
34 Dual Pole Arming Sensor Ignition Feed Open
35 Discriminating Sensor Open or Missing
36 Passenger Loop Energy Feed Open
42 Loop Energy Reserve Volatage Low
43 Driver Source Feed Low
44 Passenger Source Feed Low
51 Frontal Crash Detected
52 Data Area Full
53 Driver Side Low High Resistance
54 Passenger Side Low High Resistance
55 DERM Incompatibility
61 SIR Indicator Circuit Failure
62 Redundant Indicator Circuit Failure
71 and or 75 Internal DERM Fault
81 Driver Ignition Diode Open
82 Passenger Ignition Diode Open
83 Driver Reserve Diode Shorted
84 Passenger Reserve Diode Shorted

NOTE: SIR Code 13 will be displayed (In addition to Code 12) only if no history codes are in memory. To read history codes, a SCAN/TECH tool must be used.
Read more: The Seat Belt Question (http://www.justanswer.com/chevy/2ou1b-1990-corvette-seat-belt-light-time-dash.html#ixzz3nw6wAVal)

[GOLDCYLON]

Good to fold up and leave in the glove box along with your tool. :cheers:

[-=Jeff=-]

Nice list..

[LT5Vette]

FYI additional on SIR codes you may get a 13 that indicates no history codes in memory.
See post
http://zr1.net/forum/showpost.php?p=233291&postcount=133

Hoping that I don't need to deal with any codes, but looking forward to learning more about how the information is presented and what the codes mean.

[Dynomite]

I tried it multiple times, without success. Had to unplug the battery. Did I do something wrong?

https://www.youtube.com/watch?v=p_Ekcpjesmg

First....which code are you trying to erase?
Are you sure you fixed the issue causing the Code?

Intermittent Codes are an issue. As I recall, Kevin has a problem erasing the INFL REST code. Often when Codes do not erase it simply means the issue has not been fixed. When you say you disconnected the battery I am assuming the Code then went away? For how long did it go away?

We are right back to intermittent Code 61 as experienced in this Vacuum/MAP sensor thead.

Code 61 Vacuum/MAP sensors (http://www.zr1.net/forum/showthread.php?p=89435")

Code erasing is sensitive to timing of the pin grounding and it may require a repeat of the process several times.

Nice Video of the ALDL Code Reader.....:thumbsup:

[MuRCieLaGo]

-Was trying to erase Code 61.
-Not sure that I fixed the issue.
-When I unplugged the battery, the Code went away. For how long, I don't know, I did two 10 miles ride since yesterday and the Code still did not show up again.
-Next time a SES light shows up, I'll try some more to erase that code with your Code Eraser. Maybe that 3 seconds was a 5 seconds and that's why it didn't work?

Thanks Dynomite!

[janozr1]

Hi to all
-just vant to fix air bag light after repair ground on airb. sensor... zr1 94-
have 16 pin connector , which one is K to ground it? Clear code procedure is same like on the older cars ?

-done ground with 4th lower pin from left and got on dislpay c12 (1) and H64(9) what is that mean ?
tnx for replies ,Jano

[Dynomite]

Hi to all
-just vant to fix air bag light after repair ground on airb. sensor... zr1 94-
have 16 pin connector , which one is K to ground it? Clear code procedure is same like on the older cars ?

-done ground with 4th lower pin from left and got on dislpay c12 (1) and H64(9) what is that mean ?
tnx for replies ,Jano

Pin A is ground. the ALDL is a mirror image of this connector.

http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite13/460f6374-61e6-454d-b5c2-3084fe65fcd7.jpg

[janozr1]

thank you but i have 16 pin plug...

[janozr1]

Thanks Dave ,
will try delete code tommorow ,also hope that I will get some replays abouth fix airbag light..
jano

[Dynomite]

thank you...….but i have 16 pin plug...

Existing ALDL Code Reader for 90'-93'.........................ALDL Code Reader used with Adapter for 94'-95'
http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite13/460f6374-61e6-454d-b5c2-3084fe65fcd7.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite15/d12b8b54-98e2-474f-9e35-a18b2c7bae72.jpg
For the 16 Pin ALDL.......
Ground is Pin 4
Ground to Pin 6 is ECM
Ground to Pin 8 is PKE (Alarm System)
Ground to Pin 12 is CCM
Ground to Pin 3 is SRC
So....in the adapter if I Connect the 16 Pin end to the 12 Pin end as follows:
16 Pin (94'-95')......12 Pin (90'-93')
Connect Pin 4 to.... Pin A
Connect Pin 12 to.. Pin G (White Button)
Connect Pin 8 to.... Pin H (Black Button)
Connect Pin 3 to.... Pin C (Yellow Button)
Connect Pin 6 to.... Pin B (Green Button)
http://i287.photobucket.com/albums/ll142/dynomite007/Dynomite15/9688e8b0-83e7-4cae-ad4d-772b3f422a09.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/Dynomite15/a4a95ec5-39a9-4c08-9e8f-a518691d8357.jpg

[carguyjoe]

Can someone recommend a scan tool that works with ALDL/OBD1? I've seen the adapters that go from 12 pin to 16 pin but they have horrible reviews.

[SAHall]

Can someone recommend a scan tool that works with ALDL/OBD1? I've seen the adapters that go from 12 pin to 16 pin but they have horrible reviews.



If you want access to all the OBD1 scan features, try to track down a Tech 1 or Tech 1A scan tool and appropriate cartridges on eBay. I can send a list of useful Tech 1 cartridges if you are interested in exploring this route.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Can someone recommend a scan tool that works with ALDL/OBD1? I've seen the adapters that go from 12 pin to 16 pin but they have horrible reviews.

Are u looking to simply determine what MALF codes u have or trying to datalog ALDL datastream?

[carguyjoe]

Currently I don't have any idiot lights on, so I guess I wanted to look back at history, and be ready if anything goes wrong. I also have a Fox Body Mustang which I believe is also some form of OBD1, so I was looking for something that would get both cars. But now in looking I can see it gets expensive with all the adapters.

[XfireZ51]

Currently I don't have any idiot lights on, so I guess I wanted to look back at history, and be ready if anything goes wrong. I also have a Fox Body Mustang which I believe is also some form of OBD1, so I was looking for something that would get both cars. But now in looking I can see it gets expensive with all the adapters.

OBD1 should be the same 12pin for all makes. Code should lite SES unless it was cleared or u started the vehicle 50 times w/o recurrence of fault.

[Perry Mitchell]

The LT5 motor in my 67 Camaro flashes what I believe to be 66. Your list does not show a code 66 but doing further research I found information that says a code 66 represents a low or high power switch voltage. What does that mean? The valet key has been grounded to allow full power at all times. Any ideas?

[XfireZ51]

The LT5 motor in my 67 Camaro flashes what I believe to be 66. Your list does not show a code 66 but doing further research I found information that says a code 66 represents a low or high power switch voltage. What does that mean? The valet key has been grounded to allow full power at all times. Any ideas?

One question is which calibration are u using? What MY ZR?
Is the power switch from a 90 or 91-95? There’s a difference.
Was ur calibration modified for power switch being ON.

[Perry Mitchell]

Thank you for the response. My motor and computer are from a wrecked 91 ZR1. To the best of my knowledge, no recalibration has ever been done. The only engine modification is the installation of long tube headers. I removed the cover from the prom and found the following information: DELCO/AXFK/0277 and 060075.The instructions from the engine wiring harness kit said to simply ground the one terminal that would have otherwise run to the switch if full power all the time was desired. The motor starts fine, idles fine but is extremely rich. Any advice?

[-=Jeff=-]

Power key on a 1991 does not work by grounding the pin.. you need a 645 ohm resistor across the power key pins on the ECM. that will keep it in Full Power mode

[WVZR-1]

Perhaps the harness fabricator using this wiring diagram can explain how to accomplish what -=JEFF=- suggested. Or perhaps have the PROM 'modded'! A PROM mod might certainly be more practical.




11322.

[Perry Mitchell]

I am going to talk to Marc Haibeck about reprogramming my prom. He should be able to make any necessary changes to my early AXFK prom correct?

[-=Jeff=-]

I believe you will still need the resistor

[WVZR-1]

A conversation is certainly less expensive and a 'non-destructive' start I'd think. The harness sounds as if it was a somewhat 'generic' fabrication. Much might depend on the ECM pinning that's actually populated in the harness. A 90 doesn't have C18 or C22 populated so if the fabricator uses a very basic approach I'd think Marc could get you squared away with a 'solution'. The solution might or might NOT be PROM mod.

[Perry Mitchell]

So let's back up a minute. What does the 66 code mean? Is the system locked in valet mode or full power mode or somewhere else?

[WVZR-1]

The rest of the diagnostic page !

That's why I suggested a 'conversation' with maybe the fabricator. Marc is also a good choice! If you don't have the 'switch' and the IGN power i'd think you have immediate issues.

Do you have the '91 ECM 'pin-outs' to confirm what you have for a harness to the ECM?

11323

[Perry Mitchell]

I talked to the harness manufacture, (Ron Francis Wire Works) and he is being helpful in resolving this code 66 issue. Can someone please tell me where I can find a schematic showing the ECM pin locations with their corresponding numbers on the ECM connectors? I tried searching this forum and Marc's website to no avail. Thanks for all your help.

[WVZR-1]

PERRY


I sent you a PM. I do not recall your email from the work to correct your VSS issues. I have all that you could need for all years ECM. I believe maybe the best for you might be an entire FSM for the correct year that Ronn Francis Suggests. I can do that. I'm guessing the suggested might be a '91. I've got that and if they might have suggested a '90 I have that also. Either OR both aren't an issue!

I sent you the GREEN - C Connector Pin-Outs, also RED - B and I'll get a FSM ready for you!

-Dave

[Perry Mitchell]

Thank you Dave. I will be talking to you soon.

[Corvette95]

Jumping in late, so this a LT5 transplant? I see the post about 12 to 16 pin adapter... if you left an obd2 plug on an earlier -pre-95 (95 has the obd2 even though it is a hybrid)it could be an issue, as far as the power key, another member made a good point of the power key you are using 91 or 90. Also, do you know if the secondaries or other may have been removed? While I don't think this applies , Vetronix makes an OBD2 interface for the Tech1A that works perfect. Happy to help but WVZR-1 is the man. But I am here if I can help.