## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-66

1. Measure voltage between the ECM connector terminals B93 and B95.

Wire side of female terminals

MAP sensor 3P connector

JUMPER WIRE

Is there about 5 V?

YES – Repair the wire between ECM and the MAP sensor.

NO – Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

NOTICE

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

DTC P0238: Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

1. Check the ''On Board Diagnostic (OBD) System Check''.

Was the ''OBD System Check'' performed?

YES – Go to step 2.

NO – Go to OBD System Check.

1. Check the DTC.

Are there other DTCs P1628, P1618 (beside DTC P0238) being output?

YES – Go to DTC P1628, P1618 chart (5 V reference #2 circuit failure).

NO – Go to step 3.

1. Turn the ignition switch ON (II).

1. Check the MAP with the scan tool.

Is about atmospheric pressure indicated?

YES – Go to step 5.

NO – Go to step 7.

1. Start the engine and allow it to idle.

1. Check the MAP with the scan tool.

Is about 20 – 30 kPa (150 – 225 mmHg, 5.9 – 8.9 in. Hg) indicated?

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

NO – Go to step 7.

1. Turn the ignition switch OFF.

1. Disconnect the MAP sensor 3P connector.

a a a