Cadillac >> 91-92 Brougham 5.0 VIN E & 5.7L VIN 7

1991-1992 Cadillac Brougham


Accessing Trouble Codes

Without using A/C control panel
  • Access data link connector (DLC)
  • Jump data link connector (DLC) terminals A and B Image 1
  • Switch ignition ON. Do NOT start engine.
  • Count MIL flashes.  Note trouble codes. Compare with trouble code table.
  • Firstly trouble code 12 will be displayed 3 times
  • Trouble codes consist of 2 groups, displayed as follows:
    • First group indicates the ‘tens’ of the trouble code
    • Second group indicates the ‘units’ of the trouble code
    • A short pause separates each group
    • A long pause separates each trouble code
    • For example: Trouble code 12 displayed. Start of diagnosis.
  • Each additional trouble code will now be displayed 3 times, in ascending order

NOTE: If no additional trouble codes are stored, code 12 will continue to be displayed

Using A/C control panel
  • Switch ignition ON.
  • Simultaneously press and hold the A/C control panel ‘OFF’ and ‘Warmer’ buttons Image 3 [1] & [2]
  • When all segments of the display  Image [3] illuminate: Release the A/C control panel ‘OFF’ and ‘Warmer’ buttons
  • Parameter number ‘-00’ (A/C codes) will be displayed  Image [3]
  • Press and release the ‘HI’ button  Image [4]
  • Parameter number ‘-01’ (ECM codes) will be displayed
  • Press and release the ‘HI’ button
  • Display will alternate between ECM parameter number ‘-01’ and the trouble code at 1.6 second intervals
  • Trouble codes will be displayed in ascending order
  • Cycle will be repeated after all ECCM trouble codes have been displayed
  • If no ECM trouble codes are stored, trouble code ’00’ will be displayed
NOTE: All ECM codes start with the parameter number ‘-01’.
  • To end diagnosis:
    • Press the ‘AUTO’ button or switch ignition OFF for 10 seconds

Clearing Trouble Codes

Without using A/C control panel
  • Ensure ignition switched OFF.
  • Disconnect battery ground cable for 30 seconds
  • Reconnect battery ground cable
  • Repeat checking code procedure to ensure no trouble codes remain in ECM fault memory
  • Trouble codes can also be erased by using a Scan Tool connected to the data link connector (DLC)
Using A/C control panel
  • Access ECM trouble codes
  • During trouble code display:
  • Simultaneously press and hold ‘OFF’ and ‘LO’ buttons Image 3 [1] & [6]
  • When ’00’ is displayed:
    • Release the ‘OFF’ and ‘LO’ buttons
  • To end diagnosis:
    • Press the ‘AUTO’ button Image 3 [5], or switch ignition OFF for 10 seconds

Cadillac Brougham BCM and PCM Codes and Diagnostic Procedures


Diagnostics Basic Operation





Enter self diagnostics by simultaneously pressing and holding the “OFF” and “WARMER” buttons on the Electronic Climate Control panel until the automatic segment check begins.
2 Malfunction codes are displayed in the following order:..- ECC current codes ( parameter number -00 )1..- ECC history codes ( parameter number -00 )
3 To select a specific parameter, press “HI” to increment and “LO” to decrement the parameter number.
4 After the status light display begins, ECC error codes are displayed.  PCM codes may be displayed by selection parameter -01 and then pressing the “OUTSIDE TEMP” button.
5 Exit diagnostics by pressing the “AUTO” button
6 Pressing “OUTSIDE TEMP” switches between parameter number and parameter data
7 To over-ride a program number, while in program number display, parameter -11, pressing “WARMER” or “COLDER” will increase or decrease the program number.

Parameter Number -00


ECC Diagnostic Codes

Code Malfunction
00 No ECC system fault
10 Out-side ambient temp sensor malfunction
12 A/C evaporator inlet temp sensor malfunction
13 In-car tem sensor malfunction
19 Blower motor failure
32 PCM-ECC data problem
40 Air mix valve problem
48 Very low refrigerant pressure level
49 High engine temp
50 EVO system fault

Parameter Number -01


PCM Diagnostic Codes

Code Malfunction
00 No PCM faults
12 No engine RPM References pulses
13 Oxygen sensor circuit fault
14 Shorted coolant sensor circuit fault
15 Open coolant sensor circuit fault
21 Open throttle position sensor circuit fault
22 Shorted throttle position sensor circuit fault
23 Open MAT sensor circuit fault
24 VSS circuit fault
25 Shorted MAT sensor circuit fault
32 EGR system fault
33 Open MAP sensor circuit fault
34 Shorted MAP sensor circuit fault
42 EST/bypass circuit fault
43 ESC failure
44 Lean O2 signal
45 Rich O2 signal
51 PROM error
52 Backup fuel cal-pack missing
54 Fuel pump relay malfunction
55 A/D Converter malfunction


Number Description Range Units
-00 ECC fault codes 00-150 Code
-01 PCM fault codes 00-55 Code
-02 Program number 0-255 Counts
-03 IAC motor position 0-255 Counts
-04 MAP 0-255 KPA
-06 TPS 0-255 Counts
-07 Oxygen sensor   Volts
-08 MAT   C
-10 Ignition voltage 9.0-16.0 Volts
-11 Program number 0-100 %
-12 Vehicle speed 0-199 MPH
-19 Actual blower voltage -3.3-18 Volts
-20 Commanded blower voltage -3.3-18 Volts
-21 Engine coolant temp -40-151 C
-22 Commanded blend door position 0-255 Counts
-23 Actual blend door position 0-255 Counts
-24 Air delivery mode 0-6 Code
-25 In-car temp -40-102 C
-26 Outside air temp -40-93 C
-28 Evaporator inlet temp -40-93 C
-30 Ignition cycle counter 0-99 Counts
-31 PROM ID 0-9999 Code


Air Delivery Mode

Code Mode
0 Max A/C
1 A/C
2 Intermediate
3 Heater
4 Defrost
5 Blower delay
6 Off