PINPOINT TEST M: DTCs U1027, U1041, U1051 AND U1059

M1 RETRIEVE THE RECORDED DTCS FROM BOTH THE CONTINUOUS AND ON-DEMAND SELF-TESTS - SPEED CONTROL ACTUATOR
- Check for recorded speed control actuator DTCs from the continuous and on-demand self-test.
- Are any DTCs recorded?
- Yes : For DTC U1027, GO to M2 .
  For DTC U1041, GO to M3.
  
  For DTC U1051, GO to M4.
  
  For DTC U1059, GO to M5.
- No : GO to SYMPTOM CHART .
M2 MONITOR THE THROTTLE POSITION SENSOR (TPS)
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: PCM PID.
- Monitor the powertrain control module (PCM) TPS signal PID.
- Do the PID values agree with the throttle position?
- Yes : GO to M6.
- No : See INTRODUCTION - GASOLINE article to continue diagnosis of the TPS.
M3 MONITOR THE VEHICLE SPEED SENSOR (VSS) SIGNAL
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: ABS PID.
- Monitor the anti-lock brake system (ABS) module VSS signal PID.
- Do the PID values agree with the speed signal?
- Yes : GO to M6.
- No : REFER to ANTI-LOCK CONTROL to continue diagnosis of the VSS signal.
M4 MONITOR THE SMART JUNCTION BOX STOPLAMP SWITCH
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Smart Junction Box (SJB) PID.
- Check the speed control actuator for correct operation by monitoring the SJB stoplamp switch signal PID.
- Do the PID values agree with the stoplamp switch signal?
- Yes : GO to M6.
- No : REFER to EXTERIOR LIGHTING to continue diagnosis of the stoplamps.
M5 MONITOR THE PRNDL
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: PCM PID.
- Monitor the PCM digital transmission range (TR) sensor PID while selecting different gear positions.
- Do the PID values agree with the PRNDL display?
- Yes : GO to M6.
- No : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION to continue diagnosis of the digital TR sensor.
M6 CHECK FOR CORRECT SPEED CONTROL ACTUATOR OPERATION
- Disconnect the speed control actuator connector.
- Check for:
  - corrosion
  - pushed-out pins
- Connect the speed control actuator connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new speed control actuator. REFER to SPEED CONTROL ACTUATOR . CLEAR the DTCs. REPEAT the self-test.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.