DTC Troubleshooting: P0122 (7-1)
DTC P0122 (7-1): TP Sensor Circuit Low Voltage
1. Turn the ignition switch ON(II).
2. Check the throttle position with the scan tool.
Is there about 10% or 0.5 V when the throttle is fully closed and about 90% or 4.5 V when the throttle is fully opened?
YES - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the TP sensor and at the ECM/PCM.n
NO - Go to 3.
3. Turn the ignition switch OFF.
4. Disconnect the TP sensor 3P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between the TP sensor 3P connector terminals No. 1 and No. 3.
TP SENSOR 3P CONNECTORWire side of female terminalsSG2
(GRN/BLK)VCC2
(YEL/BLU)
Is there about 5 V?
YES - Go to 7.
NO - Go to 14.
7. Turn the ignition switch OFF.
8. At the sensor side, measure resistance between the TP sensor 3P connector terminals No. 1 and No. 2 with the throttle fully closed.
TP SENSOR 3P CONNECTORTerminal side of male terminalsSG2TPS
Is there about 0.5-0.9 kW?
YES - Go to 9.
NO - Replace the throttle body.n
9. Measure resistance between the TP sensor 3P connector terminals No. 2 and No. 3 with the throttle fully closed.
TP SENSOR 3P CONNECTORTerminal side of male terminalsTPSVCC2
Is there about 4.5kW?
YES - Go to 10.
NO - Replace the throttle body.n
10. Disconnect ECM/PCM connector A (31P).
11. At the wire harness side, check for continuity between TP sensor 3P connector terminal No. 2 and body ground.
TP SENSOR 3P CONNECTORTPS
(RED/BLK)Wire side of female terminals
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (A15) and the TP sensor.n
NO - Go to 12.
12. Connect ECM/PCM connector terminal A15 and body ground with a jumper wire.
ECM/PCM CONNECTOR A (31P)Wire side of female terminalsTPS
(RED/BLK)JUMPER WIRE
13. At the wire harness side, check for continuity between TP sensor 3P connector terminals No. 2 and body ground.
TP SENSOR 3P CONNECTORTPS
(RED/BLK)Wire side of female terminals
Is there continuity?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n
NO - Repair open in the wire between the ECM/PCM (A15) and the TP sensor.n
14. Measure voltage between ECM/PCM connector terminals A10 and A20.
ECM/PCM CONNECTOR A (31P)Wire side of female terminalsSG2
(GRN/BLK)VCC2
(YEL/BLU)
Is there about 5 V?
YES - Repair open in the wire between the ECM/PCM (A20) and the TP sensor.n
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM
