DTC P1238: Fuel Pump Secondary Circuit Malfunction
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
P1238 - FUEL PUMP SECONDARY CIRCUIT MALFUNCTION
| Description: | This DTC indicates the fuel pump driver module (FPDM2) detected a fuel pump secondary circuit concern. The FPDM2 sends a message to the powertrain control module (PCM) through the fuel pump monitor (FPM2) circuit, indicating this concern was detected. The PCM sets the DTC when the message is received. | ||
| Possible Causes: |
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| Diagnostic Aids: | The FPDM2 sends a 75% duty cycle (750 ms on, 250 ms off) through the FPM2 circuit to the PCM while the concern is being detected by the FPDM2. If the concern is no longer detected, the PCM returns to sending an all OK (50% duty cycle) message to the PCM. The FPDM2 controls pump speed by supplying a variable ground on the FP2RTN circuit. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to KB: Fuel Pump Driver Module STEP KB73. | ||