Inspection Procedure
- PROBLEM VERIFICATION
- Turn ignition switch to ON position.
- Using a Hi-Scan (Pro), monitor the TPS signals while slowly opening the throttle.
Specification (TPS signal):
- 0.2 ~ 0.8 V at Closed Throttle
- 4.3 ~ 4.8 V at Wide Open Throttle
- Refer to CHARACTERISTIC CURVE in P0121 about any other throttle angle.
Is signal within specification and consistent with the normal curve?
- No: Go to next step.
- Yes: Problem is intermittent or was repaired and ECM memory was not cleared. See INTERMITTENT PROBLEM INSPECTION PROCEDURE ..
- CHECK TPS AND ECM CONNECTORS
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. See CONNECTOR INSPECTION PROCEDURE .
Are all connectors good?
- Yes: Go to next step.
- No: Repair or replace it.
- CHECK TPS RESISTANCE
- Turn ignition switch to OFF and disconnect TPS connector.
- Measure resistance between the terminal 1 and 2 of TPS connector.
- Measure resistance between the terminal 2 and 3 of TPS connector.
Specification (TPS resistance at any temperature):
- Terminal 1 and 2: 0.71 ~ 1.38 kΩ at Closed Throttle 2.7 kΩ at Wide Open Throttle
- Terminal 2 and 3: 1.6 ~ 2.4 kΩ at all throttle position
Is each resistance within specification?
- Yes: Go to next step.
- No: Replace TPS.
- CHECK REFERENCE VOLTAGE TO TPS
- Turn ignition switch to OFF position and disconnect TPS connector.
- Turn ignition switch to ON position.
- Measure voltage between terminal 3 of the TPS harness connector and chassis ground.
Specification (Voltage): approximately 5V
Is voltage within specification?
- Yes: Go to next step.
- No: Repair open or short to chassis ground in harness.
- CHECK FOR SHORT TO GROUND IN HARNESS
- Turn ignition switch to OFF position, and then disconnect TPS and ECM connectors.
- Measure resistance between terminal 1 and 2 of the TPS harness connector.
- Measure resistance between terminal 1 of the TPS harness connector and chassis ground.
Specification (Resistance): infinite
Does each resistance indicate open?
- Yes: Proceed with ECM PROBLEM INSPECTION PROCEDURE .
- No: Repair short or short to chassis ground in harness.