P1541

P1541

Fuel Pump Relay Output Stage - Open Circuit

Function
A protective circuit is integrated in the DME control module to prevent the fuel pump from running when the engine is off and the ignition is on. The DME control module transmits a ground signal to the fuel pump relay from an engine speed of 25 rpm.

Diagnosis conditions

P1501 and P1541
A fault is detected and stored in memory only in the after-run of the ECM program, i.e. when the ignition is switched off after the engine has been running.

P1502
A fault is detected and stored in the memory when the engine speed is over 80 rpm and the battery voltage lies between 7.5 and 17 V.

NOTE: The triggering wire is monitored for the fuel pump relay, terminal 85.

P1501-P1541:

Wiring Diagram







Diagnosis Procedure

DTC P1501







DTC P1502







DTC P1541







1 Check fuel pump relay.

1. Remove fuel pump relay.
2. Connect ohmmeter to terminals 85 and 86.
Display: approx. 75 ohms

2 Check wiring from DME control module to fuel pump relay for short circuit to ground.

1. Connect special tool 9616 to wiring harness (DME control module connector).
2. Remove fuel pump relay.
3. Connect ohmmeter to special tool 9616, pin 63, and ground.
Display: Infinity ohm

If 0 - 5 ohms is displayed, check wiring for chafing and pinching damage.

3 Check wiring from DME control module to fuel pump relay for short circuit to B+.

1. Connect special tool 9616 to wiring harness (DME control module connector).
2. Remove fuel pump relay.
3. Connect voltmeter to special tool 9616, pin 63, and ground.
Ignition on.
Display: 0 V

4 Check wiring from DME control module to fuel pump relay for continuity.

1. Connect special tool 9616 to wiring harness (DME control module connector).
2. Remove fuel pump relay.
3. Connect ohmmeter to special tool 9616, pin 63, and fuel pump relay slot, pin 6 (terminal 85).
Display: 0 - 5 ohms

If Infinity ohm is displayed, check connector X 2/3, pin 23, and check wiring harness for chafing and pinching damage.