Signal Too Low

ECM-2400 FUEL PUMP (FP) RELAY
SIGNAL TOO LOW

Checking for intermittent faults



- Activate the fuel pump (FP) relay.

The fuel pump (FP) relay should click when it is activated.

Does the fuel injection relay click?
Yes - Continue below.
No - Skip to "Checking the Connector"


Intermittent fault



Check the cable between control module terminal # 45B (# B57) and fuel pump (FP) relay terminal # 3 (31b). Check for an intermittent short-circuit to ground according to [1][2]Checking Wiring and Terminals. Intermittent Faults Check for an intermittent open-circuit according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Remedy as necessary.


Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
--Testing Complete--


Checking the connector



- Ignition off
- Check the fuel pump (FP) relay connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Permanent Fault

- Remedy as necessary.

Other information
- To access/replace the fuel pump (FP) relay, Replacing Relay In the Main Fuse Box


Checking the connector



- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Activate the fuel pump (FP) relay.

The fuel pump (FP) relay should click when it is activated.
If the fuel pump (FP) relay now clicks, the cause of the fault was loose connections in the connector.

Remedy as necessary.

Other information
- To access/replace the fuel pump (FP) relay, Replacing Relay In the Main Fuse Box

Does the fuel injection relay click?
Yes - Testing Complete.
No - Continue below.


Checking the wiring



Check the signal cable between control module terminal # B45 and fuel pump (FP) terminal 4 (31b). Check for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault Check for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Remedy as necessary.

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- To access/replace the fuel pump (FP) relay, Replacing Relay In the Main Fuse Box
- For information about signals, Pinout Values and Diagnostic Parameters


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect connectors, reinstall components
- Ignition on.
- Activate fuel pump (FP).

The fuel pump should start.

Does the fuel pump (FP) start?
Yes - Testing Complete.
No - Continue below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt