HVAC Trouble codes

Did you know that you can access your
Engine(and other) trouble codes through the Climate Control? Did you also
know that you can accurately monitor the engine RPM, vehicle speed,
coolant temp, and others? If so, good job! If not, look at this!

This is for 94-96's!!

*Please note, some of this was info copied directly from ISSF.



Instructions for putting ACC in diagnostic mode -
- turn ignition to ON position (or start vehicle)
- press and hold the "temp up" and "OFF" buttons at the same time until the unit does a full segment check.
- Release the buttons.
- Display should read -00... you are now in diagnostic mode
- Using the fan up/down buttons, select desired function from above
- press the "middle" Button. It should be in the top right corner on the CC.
- To Exit the trouble code area, and go back to the -00 display, hit the "Middle" button again.

Have fun!

You will see -00. You can change the funtion(it will say -01, -02, etc)
with the fan up, and down buttons. Here is a list of what all the -00
numbers mean.


Here are the most common you will need to know

-00 PCM diagnostics codes
-01 CCM Diagnostic trouble codes
-02 HVAC Diagnostic trouble codes
-03 SIR Diagnostic trouble codes
-04 ABS/TC Diagnostic trouble codes
-06 Engine RPM
-08 Coolant Temp (°F) - Reading taken at Cylinder head sensor, typically 20* cooler than the -24 reading
-14 Vehicle speed
-24 Coolant Temp (°C) - Reading taken at the Water Pump sensor, This is what the PCM uses to control the fans.



Diagnostic Pointers and Parameters

No. Description Range Default Value Units


-00 PCM System Diagnostic Trouble Codes ...............................................
-01 CCM System Diagnostic Trouble Codes ...............................................
-02 ACAC (HVAC) System Diagnostic Trouble Codes .......................................
-03 SIRSystem Diagnostic Trouble Codes ................................................
-04 ABS/TC System Diagnostic Trouble Codes ............................................
-05 Program number .......................... 0-255 ....... n/a ............. Counts
-07 Command Blower Motor Speed .............. 0-128 ....... n/a ............. Counts
-14 Vehicle speed ........................... 0-199 ....... n/a ................ MPH
-15 HVAC Learn Mode (Temp Cal) .............. -5 to +5 F .. 0 F ............ Degrees
-18 Sun Load Sensor ......................... 0-255 ....... n/a ............. Counts
-20 Current Temperature Valve Position ...... 0-255 ....... 240 ............. Counts
-22 Temperature Valve Position (Full Cold) .. 180-250 ..... 180 ............. Counts
-23 Temperature Valve Position (Full Hot) ... 5-60 ........ 60 .............. Counts
-24 Engine Coolant Temperature .............. -40 to 151 .. n/a ............ Celsius
-25 Command Temperature Valve Position ...... 0-255 ....... 128 ............. Counts
-27 Air Delivery Mode ....................... 0-9 ......... n/a ... Code (see below)
-28 Inside Air Temperature Sensor ........... 0-255 ....... n/a ............. Counts
-31 Outside Air Temperature Sensor .......... 0-255 ....... n/a ............. Counts
-37 EEPROM Revision Number .................. 0-0000 ...... n/a ............... Code

Here is a list of the trouble codes.
These were posted for the Fleetwood, so some might be slightly
different, or not apply.


PCM diagnostics codes... (-00)

11: malfunction indicator lamp (MIL) circuit
13: Bank 1 (left) heated o2 sensor (open circuit)
14: Engine coolant coolant temperature sensor (siganl voltage low, high tempurature indicated)
15: Engine coolant coolant temperature sensor (siganl voltage high, low tempurature indicated.
16: Distributor ignition system (low resolution pulse)
18: injector circuits.
21: Throttle position sensor TPS circuit (signal voltage high)
22: Throttle position sensor TPS circuit (signal voltage low)
23: Air intake temperature IAT sensor circuit (signal voltage high, low temperature indicated.
24: Vehicle speed sensor (VSS) circuit.
25: Air intake temperature IAT sensor circuit (signal voltage low, high temperature indicated
26: Evaporative emission (EVAP) canister purge solenoid circuit.
27: Exhaust gas recirculation (EGR) vaccum control signal solenoid valve circuit
28: transmission range (TR) pressure switch assembly fault
29: Secondary air injector (AIR) pump circuit.
32: Exhaust gas recirculation (EGR) 1 of 2
33: Manifold absolute Pressure (MAP) sensor circuit (signal voltage high- vacuum low)
34: Manifold absolute Pressure (MAP) sensor circuit (signal voltage low-vacuum high)
36: Distrigutor ignition system (faulty high resolution pulse or extra low resolution pulse detected.)
37: brake switch stuck on
38: brake switch stuck off
41: Ignition control (IC) circuit (open)
42: Ignition control (IC) circuit (shorted or grounded circuit)
43: Knock sensor (KS) circuit
44: Bank 1 (left) heated O2 sensor circuit (lean exhaust indicated)
45: Bank 1 (left) heated O2 sensor circuit (rich exhaust indicated)
46: PASS-key II circuit
47: Knock sensor circuit or control module missing.
48: Mass air flow (MAF) sensor circuit
50: system voltage low
51: EEPROM programming error
53: Sytem voltage high
55: Fuel lean monitor
58: Transmission fluid temp. (TFT) sensor circuit low (High temperature indicated)
59: Transmission fluid temp. (TFT) sensor circuit high (Low temperature indicated)
63: Bank 2 (right) Heated oxygen sensor(HO2S) circuit (open circuit)
64: Bank 2 (right) Heated oxygen sensor(HO2S) circuit (lean exhaust indicated)
65: Bank 2 (right) Heated oxygen sensor(HO2S) circuit (rich exhaust indicated)
66: A/C pressure refrigerant circuit (open or shorted)
67: A/C pressure refrigerant circuit (pressure sensor or A/C clutch circuit problem)
68: A/C relay circuit (shorted circuit)
69: A/C clutch circuit
70: A/C clutch relay driver circuit
72: vehicle speed sensor loss
73: Pressure control solenoind (PCS) circuit (current error)
74: Traction control system (TCS) circuit low
75: Transmission system voltage low
77: Primary cooling fan relay control circuit (not used with V08 option)
78: Secondary cooling fan relay control circuit
79: Trsnsmission fluid overtemp
81: Transmission 2-3 shift solenoid circuit
82: Transmission 1-2 shift solenoid circuit
84: Transmission 3-2 control solenoid circuit
85: Transmission TCC stuck "ON"
90: Transmission TCC solenoid circuit
95: Change oil lamp circuit
96: low oil lamp circuit
97: VSS output circuit

CCM Diagnostic trouble codes (-01)

20: RAP enable circuit (circuit shorted to battery)
21: RAP enable circuit (circuit open or shorted to ground)
22: DIL enable circuit (circuit shorted to battery)
23: DIL enable circuit (circuit open or shorted to ground)
24: Curtesy output circuit (circuit shorted to battery)
25: Curtedy output circuit (circuit open or shorted to ground)
26: VES output circuit (circuit open or shorted to ground)
27: VES output circuit (circuit shorted to battery)
28: VES tracking tracking error (circuit open, shorted to ground, or shorted to battery)
30: "PASS KEY FAULT" telltale circuit (circuit shorted to battery)
31: "PASS KEY FAULT" telltale circuit (circuit open or shorted to ground)
32: Fuel enable circuit (circuit shorted to battery)
33: Fuel enable circuit (circuit open or shorted to ground)
34: Heaflamp enable circuit (circuit shorted to battery)
35: Park lamp enable circuit (circuit shorted to battery)
36: DRL enable circuit (circuit shorted to battery)
37: DRL enable circuit (circuit open or shorted to ground)
38: EEPROM calibration error
39: EEPROM calibration id error
40: Delay pot circuit (circuit shorted to ground)
41: Dealy pot circuit (circuit open or shorted to battery)
42: Key resistor circuit (circuit shorted to ground)
43: Key resistor circuit (circuit open or shorted to battery)
44: Steering wheel sensor circuit (circuit open or shorted to ground)
45: Steering wheel sensor circuit (circuit open or shorted to battery)
46: CCM internal failure
47: Canadian select input error

HVAC Diagnostic trouble codes (-02)

01: Outside air tempurature sensor circuit (circuit open)
02: Outside air tempurature sensor circuit (circuit shorted)
03: In car air tempurature sensor circuit (circuit open)
04: In car air tempurature sensor circuit (circuit shorted)
05: Sun load sensor circuit (circuit open)
06: Sun load sensor circuit (circuit shorted)
10: Air mix motor circuit (circuit open)
11: Air mix motor circuit (circuit shorted)
26: Serial Data Communication (circuit shorted to battery, shorted to ground, or circuit open)
27: Invalid EEPROM detected

SIR Diagnostic trouble codes (-03)

15: Passenger deployment loop resistance high
16: Passenger deployment loop resistance low
17: Passenger deployment loop open
21: Driver deployment loop resistance high
22: Driver deployment loop resistance low
24: Deployment loop voltage low
25: Deployment loop shorted to ignition
26: Driver's deployment loop open
35: ADS (auxiliary discriminating sensor) missing/shorted to ground
36: ADS closed/shorted to voltage
51: Frontal crash detected
52: Crash data area full
61: Lamp circuit failure
62: Redundant lamp circuit failure
71: Internal SDM malfuntion

ABS/TC Diagnostic trouble codes (-04)

21: RF wheel speed sensor circuit malfunction
23: RF wheel speed sensor circuit continuity malfunction
25: LF wheel speed sensor circuit malfunction
27: LF wheel speed sensor circuit continuity malfunction
28: Wheel speed sensor circuit frequency malfunction
31: RR wheel speed sensor circuit malfunction
33: RR wheel speed sensor circuit continuity malfunction
35: LR wheel speed sensor circuit malfunction
37: LR wheel speed sensor circuit continuity malfunction
41: Right front valve soleniod malfunction
42: RH outlet valve solenoid malfunction
45: Left front valve solenoid malfunction
46: LF outlet valve solenoid malfunction
47: ASV prime line solenoid malfunction
48: USV pilot valve solenoid malfunction
51: Right rear valve solenoid malfunction
52: RR outlet valve solenoid malfunction
55: Left rear valve solenoid malfunction
56: LR outlet valve solenoid malfunction
57: TCC disable relay output malfunction
58: EBTCM internal adjuster assembly malfunction
61: Pump motor or pump motor relay malfunction
62: Traction disable switch used or RPM signal malfunction
63: valve solenoid relay malfunction
64: Throttle position signal malfunction
65: Adjuster assembly circuit malfunction
66: Adjuster assembly control malfunction
67: Throttle position sensor comparison malfunction
71: EBTCM internal malfunction
72: Serial data link malfunction
73: Spark retard monitoring malfunction
85: Low voltage.

Here is a link to both info sources used.

http://www.impalassforum.com/vBulletin/showthread.php?p=2034815#post2034815

http://www.impalassforum.com/vBulletin/showthread.php?t=183831

Here are links to Online listings of trouble codes, in case these are off.



Here is a list of trouble codes.

OBD-I codes 95 -

http://www.troublecodes.net/GM/95_57P.shtml


OBD-I Codes 94 -

http://www.troublecodes.net/GM/94_57P.shtml

OBD-I Codes 93

http://www.troublecodes.net/GM/93_577_tbi.shtml

OBD-I Codes 92

http://www.troublecodes.net/GM/92_577_tbi.shtml



OBD-I Codes 91


http://www.troublecodes.net/GM/91_577_tbi.shtml

This needs to be a Sticky (or whatever ya call it) in the FAQ section!!!

Thanks for posting this great info Robert!!!

Larry

Had trouble finding this so I thought I would revive it for the "new" guys.....