SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSOLDSMOBILE2004BRAVADA RWDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 117 (ENGINE CONTROLS - SELF-DIAGNOSTICS)DIAGNOSTIC TESTSDTC P1640: CONTROL MODULE OUTPUT CIRCUITDIAGNOSTIC PROCEDURE
2004 Oldsmobile Bravada RWD

Diagnostic Procedure

2004 Oldsmobile Bravada RWDSECTION Diagnostic Procedure
WARNING: This page is about a different car, the 2002 Saturn LW200, 2002 Saturn L200, and 2002 Saturn L100. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: If DTC P0753, P0758 or P1860 is also set, diagnose that DTC first. P1640 will also set if a 1-2 or 2-3 shift solenoid or TCC solenoid fault exists. See appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.
  1. Turn ignition ON, engine OFF. Using scan tool, review DTC P1640 failure record. Observe A/C RELAY CKT OPEN SHORT TO GND. If scan tool reads YES, see DTC P1640: A/C RELAY CONTROL CIRCUIT LOW VOLTAGE  . If scan tool reads NO, go to next step.
  2. Using scan tool, observe A/C RELAY CKT SHORT TO VOLTS. If scan tool reads YES, see DTC P1640: A/C RELAY CONTROL CIRCUIT HIGH VOLTAGE  . If scan tool reads NO, go to next step.
  3. Using scan tool, observe MODULE DRIVER OVERVOLT and MODULE DRIVER OVERTEMP. If scan tool reads YES for either, record all PCM DTCs and reprogram PCM. See PCM REPROGRAMMING  under PROGRAMMING. If this fault returns, replace and reprogram the PCM. If scan tool reads NO for both, see DIAGNOSTIC AIDS  .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.