P1501
P1501
End Stage Fuel Pump Relay - Short Circuit to Ground.
P1502
End Stage Fuel Pump Relay - Short Circuit to Plus.
P1541
End Stage Fuel Pump Relay - Interruption.
Function:
To prevent the fuel pump from running with ignition on and engine not running, a safety circuit is integrated in the ECM. Beginning with an engine speed of 25 rpm, the ECM supplies a ground connection to the fuel pump relay.
Diagnostic Conditions:
P1501 and P1541:
A fault is recognized and stored in memory only in the after-run of the ECM program, meaning, when the ignition is switched off after the engine has run.
P1502:
A fault is recognized and stored in memory when the engine speed is higher than 80 rpm and the battery voltage is between 7.5 Volt and 17 Volt.
NOTE: The signal wiring for the fuel pump relay is monitored via terminal 85.
Wiring Diagram:
Image Legend:
A. Fuel pump relay
Diagnostic Procedure:
DTC P1501:
DTC P1502:
DTC P1541:
1. Check fuel pump relay.
1. Remove fuel pump relay.
2. Connect ohmmeter to terminal 85 (minus) and terminal 86 (plus).
Specified Value: approx. 75 Ohms.
2. Check wiring from ECM to fuel pump relay for short circuit to ground.
1. Connect special tool 9616 to wiring harness.
2. Remove fuel pump relay.
3. Connect ohmmeter to special tool 9616, pin 63 and to ground.
Specified Value: Infinite Ohms.
If 0 - 5 Ohms is displayed, check wiring harness for chafing and pinching damage.
3. Check wiring from ECM to fuel pump relay for short circuit to B+.
1. Connect special tool 9616 to wiring harness.
2. Remove fuel pump relay.
3. Connect voltmeter to special tool 9616, pin 63 and to ground.
Ignition on.
Specified Value: 0 Volt.
4. Check wiring from ECM to fuel pump relay for continuity.
1. Connect special tool 9616 to wiring harness.
2. Remove fuel pump relay.
3. Connect ohmmeter to special tool 9616, pin 6:3, and fuel pump relay socket, pin 6 (terminal 85).
Specified Value: 0 - 5 Ohms.
If infinite Ohms is displayed, check connector X 3/1, pin 5 and wiring harness for chafing and pinching damage.