LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 1994 >> DeVille Base >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Self-Diagnostics >> Trouble Codes >> Code I037 Loss Of ACP Data

Code I037 Loss Of ACP Data

  1. If this code is set with any other codes, see appropriate MULTIPLE DATA COMMUNICATION CODES procedure. If this code is set by itself, IPC is not able to exchange data with ACP. Problem solution will be one of following:
    • An open in Tan wire circuit between ACP and PCM and a second open between ACP and either RSS module (4.6L) or DERM (4.9L).
    • An open in ACP power or ground circuits.
    • A faulty ACP.

    Diagnostic Energy Reserve Module (DERM) is located directly above brake pedal. DERM has Yellow connector and wiring harness. A/C Programmer (ACP) is located to left of PCM, behind glove box.

  2. When this code is present, CCC panel will display "- - -" for outside and set temperatures, defrost mode will be selected, A/C clutch will be disabled and blower will run at constant 6 volts.
  3. Enter self-diagnostics. See ENTERING SELF-DIAGNOSTICS  under SELF-DIAGNOSTICS. If Code I037 sets as a current code (I037C), go to step 5). If Code I037 sets as a history code (I037H), there is an intermittent problem. Locate ACP connector.
  4. If only Code I037 is set, check for power to ACP by backprobing ACP connector terminals C12 (Brown wire) and C13 (Orange wire) for battery voltage when ignition is in RUN position. Refer to Figure . Check ACP connector terminal C1 for ground continuity. Check across ACP connector terminals C10 and C11 for open in serial data line circuit. Check for an open in Tan wire circuit between ACP and PCM.
  5. Remove ACP harness connector. Using DVOM, measure voltage at ACP harness connector terminal C11 (Tan wire). See Figure . Terminal C11 (Tan wire) is serial data line to IPC. If voltage does not fluctuate between 3 and 5 volts at this terminal, repair open in Tan wire circuit between ACP and PCM.
  6. If voltage is fluctuating between 3 and 5 volts, measure voltage between ACP harness connector terminals C13 and C1, and between C12 and C1. If both voltage tests are less than 10 volts, repair ground in Black/White wire circuit from terminal C1. If only terminal C12 has less than 10 volts, repair ignition power circuit (Brown wire).
  7. If only C13 has less than 10 volts, repair short in battery power circuit (Orange wire). If both voltage tests are 10 volts or more, check resistance between harness connector terminal C1 and ground. If resistance is greater than one ohm, repair ground. If resistance is less than one ohm, check for terminal and connection damage. If all connections are good, replace ACP. After all repairs are completed, clear all codes and verify correct operation.
scientia non olet · About LEMON Manuals