April 5, 2026: LEMON Manuals is launched! Read the announcement.

Driver Complaint Sheet

Engine performance problem (odor, surge, fuel economy)

Emission problem

If the "check engine" light is not on, normal checks that would be performed on cars without CCC should be done first.

If generator or coolant light is on with the check engine light, they should be diagnosed first.

Inspect for poor connections at coolant sensor, M/C solenoid, etc., and poor or loose vacuum hoses and connections. Repair as necessary.

Intermittent check engine light but no trouble code stored -
- Check for intermittent connection in circuit from:
  - Distributor module terminal R to ECM terminal 10.
  - Battery to ECM terminals C and R.
  - ECM terminal U to engine ground.
- Loss of long terminal memory Grounding dwell lead for 10 seconds with "test" lead ungrounded should give code 23. It should be retained after engine is stopped and ignition turned to run position. If it is not, ECM is defective.
Stalling, Rough Idle or Improper Idle Speed - See idle speed control.
Poor Performance and/or Fuel Economy - See EST diagnosis.
Poor Full Throttle Performance - See Chart 5 (if equipped with TPS)
All Other Complaints - Make system performance check on warm engine (upper radiator hose hot)
The system performance check should be performed after any repairs to the CCC system have been made.

Fig 1: System Performance Check

G09339976

Courtesy of GENERAL MOTORS COMPANY

Fig 2: Chart No. 2 Dwell Fixed Between 10-50°

G09339977

Courtesy of GENERAL MOTORS COMPANY

Fig 3: Chart No. 1 Dwell Fixed Under 10°

G09339978

Courtesy of GENERAL MOTORS COMPANY

Fig 4: Chart No. 3 Dwell Fixed Over 50°

G09339979

Courtesy of GENERAL MOTORS COMPANY

Fig 5: Chart No. 4 "Check Engine" Lamp Inoperative

G09339980

Courtesy of GENERAL MOTORS COMPANY

Fig 6: Chart No. 6 Won't Flash Code 12

G09339981

Courtesy of GENERAL MOTORS COMPANY

Fig 7: Chart No. 5 TPS Switch Circuit Check

G09339982

Courtesy of GENERAL MOTORS COMPANY

Fig 8: Trouble Code 12 All Except 3.8L VIN Code K

G09339983

Courtesy of GENERAL MOTORS COMPANY

Fig 9: Trouble Code 12 3.8L VIN Code K

G09339984

Courtesy of GENERAL MOTORS COMPANY

Fig 10: Trouble Code 13

G09339985

Courtesy of GENERAL MOTORS COMPANY

Fig 11: Trouble Code 14

G09339986

Courtesy of GENERAL MOTORS COMPANY

Fig 12: Trouble Code 15

G09339987

Courtesy of GENERAL MOTORS COMPANY

Fig 13: Trouble Code 21

G09339988

Courtesy of GENERAL MOTORS COMPANY

Fig 14: Trouble Code 23

G09339989

Courtesy of GENERAL MOTORS COMPANY

Fig 15: Trouble Code 24

G09339990

Courtesy of GENERAL MOTORS COMPANY

Fig 16: Trouble Code 32

G09339991

Courtesy of GENERAL MOTORS COMPANY

Fig 17: Trouble Code 34 Vacuum Sensor Circuit

G09339992

Courtesy of GENERAL MOTORS COMPANY

Fig 18: Trouble Code 34 Map Sensor (Non-Turbo Models)

G09339993

Courtesy of GENERAL MOTORS COMPANY

Fig 19: Trouble Code 34 Map Sensor (Turbo Models)

G09339994

Courtesy of GENERAL MOTORS COMPANY

Fig 20: Trouble Code 35

G09339995

Courtesy of GENERAL MOTORS COMPANY

Fig 21: Trouble Code 42

G09339996

Courtesy of GENERAL MOTORS COMPANY

Fig 22: Trouble Code 45

G09339997

Courtesy of GENERAL MOTORS COMPANY

Fig 23: Trouble Code 44 Or Trouble Code 44 & 55 Together

G09339998

Courtesy of GENERAL MOTORS COMPANY

Fig 24: Trouble Codes 51-54 Code 51

G09339999

Courtesy of GENERAL MOTORS COMPANY

Fig 25: Trouble Code 55

G09340000

Courtesy of GENERAL MOTORS COMPANY

Fig 26: EST Check

G09340001

Courtesy of GENERAL MOTORS COMPANY

Fig 27: EST Diagnosis Check

G09340002

Courtesy of GENERAL MOTORS COMPANY

Fig 28: Engine Cranks, But Will Not Start

G09340003

Courtesy of GENERAL MOTORS COMPANY

Fig 29: Idle Speed Control Check*

G09340004

Courtesy of GENERAL MOTORS COMPANY

Fig 30: Air Management Check (Exc 3.8L VIN K, 4.1L, 4.4L VIN J, 5.0L VIN H & 5.7L VIN L, 6 & 8)

G09340005

Courtesy of GENERAL MOTORS COMPANY

Fig 31: Air Management Check (3.8L VIN K, 4.4L VIN J, 5.0L VIN H & 5.7L VIN L, 6 & 8)

G09340006

Courtesy of GENERAL MOTORS COMPANY

Fig 32: TCC Electrical Diagnosis (Without EGR Bleed)

G09340007

Courtesy of GENERAL MOTORS COMPANY

Fig 33: Air Management Check 4.1L VIN 4

G09340008

Courtesy of GENERAL MOTORS COMPANY

Fig 34: TCC/EGR Bleed Solenoid Electrical Diagnosis

G09340009

Courtesy of GENERAL MOTORS COMPANY

Fig 35: Purge Valve Check

G09340010

Courtesy of GENERAL MOTORS COMPANY

Fig 36: Heated EFE Check

G09340011

Courtesy of GENERAL MOTORS COMPANY

Fig 37: TCC/EGR Bleed Solenoid Clutch Operation Check

G09340012

Courtesy of GENERAL MOTORS COMPANY

Fig 38: Pulsair Solenoid Check

G09340013

Courtesy of GENERAL MOTORS COMPANY

Fig 39: EFE Check (Vacuum-Servo Type)

G09340014

Courtesy of GENERAL MOTORS COMPANY

Fig 40: Diverter Valve Check 3.8L Engine (Except Turbo)

G09340015

Courtesy of GENERAL MOTORS COMPANY

Fig 41: EGR Check (Except Turbo)

G09340016

Courtesy of GENERAL MOTORS COMPANY

Fig 42: EFE/EGR Check 3.8L Turbo Only

G09340017

Courtesy of GENERAL MOTORS COMPANY

Fig 43: EGR Check 4.1L, 4-Spd. Auto. Trans. With Auxiliary Vacuum Pump

G09340018

Courtesy of GENERAL MOTORS COMPANY

Fig 44: Wiring Diagram for 3.81 (VIN A and K) Engines

G09340019

Courtesy of GENERAL MOTORS COMPANY

Fig 45: Wiring Diagram for 3.8L (VIN 3), 4.1L and 4.9L (VIN T AND W) Engines

G09340020

Courtesy of GENERAL MOTORS COMPANY

Fig 46: Wiring Diagram for All Other General Motors Engines

G09340021

Courtesy of GENERAL MOTORS COMPANY