## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-110

1. Check the RP sensor signal circuit for short.

Wire side of female terminals

RP sensor 3P connector

JUMPER WIRE

Is a problem found?

YES – Repair the RP sensor ground circuit.

NO – Go to step 13.

1. Measure the resistance of RP sensor.

Is there 0.9 – 1.3 ohms?

YES – Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

NO – Replace the RP sensor.

NOTICE

The battery power supply short circuit to 5 V power supply damages the ECM.

DTC P1224: Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage

1. Check the DTC.

Are there other DTCs P1625, P1626 (beside DTC P1224 being output?

YES – Go to DTC P1625, P1626 chart (5 V reference #1 circuit failure).

NO – Go to step 2.

1. Check for the following conditions:

- Damaging APP sensor
- An incorrect APP sensor fixing
- Damaging accelerator pedal and wire

Is a problem found?

YES – Repair as necessary.

NO – Go to step 3.

1. Turn the ignition switch ON (II).

1. Check the TP (APP) with the scan tool.

Is about 0 % indicated?

YES – Go to step 5.

NO – Go to step 6.

1. Press the accelerator pedal.

Is about 0 (idle) – 100 % (WOT) indicated?

YES – Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the APP sensor and at the ECM.

NO – Go to step 6.

1. Turn the ignition switch OFF.

1. Disconnect the APP sensor 6P connector.

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