2002 Ford Mustang V6 My car started having a new problem yesterday. When I drive down the road randomly the pedal loses rpm's. For instance I'll be going 40mph and then there is no resistance on the pedal as if I am idling. I have to put the car in neutral turn it off and turn it back on while it's still rolling to get it to work again. It has happened to me 3 times in the last 2 days. I am getting the following error codes: P0420: Catalyst System Efficiency Below Threshold Bank 1 CONFIRMED and P1233: Fuel Pump Driver Module Off-Line CONFIRMED

About 3 months ago I had a used transmission put in by my mechanic and it came with a 6 month warranty. I was wondering if any of these error codes have anything to do with the transmission so it would be covered under the warranty or are these issues not relevant


The problems you are experiencing will have nothing to do with the transmission. Here is what the code explanation is. My feeling is it's with the Fuel pump driver module. It may be going bad.

Code: P1233 - Fuel System Disabled or Offline

Description: The PCM monitors the fuel pump monitor (FPM) circuit from the fuel pump driver module (FPDM). With the key on, the FPDM continuously sends a duty cycle signal to the PCM through the FPM circuit. The test fails if the PCM stops receiving the duty cycle signal.

Possible Causes: Inertia fuel shutoff (IFS) switch needs to be reset Open FPDM ground circuit Open circuit to FPDM PWR RLY Open FPDM PWR circuit Open or shorted FPM circuit (engine should start) Damaged IFS switch Damaged FPDM PWR RLY Damaged FPDM Damaged PCM Also for Mustang: Open B+ circuit to the constant control relay module (CCRM) pin 11 Open ground to CCRM pin 18 Damaged CCRM

Diagnostic Aids: The PCM expects to see one of the following duty cycle signals from the FPDM on the FPM circuit: 1) 50% (500 ms on, 500 ms off), all OK. 2) 25% (250 ms on, 750 ms off), FPDM did not receive a fuel pump (FP) duty cycle command from the PCM, or the duty cycle that was received was invalid. 3) 75% (750 ms ON, 250 OFF), the FPDM has detected a fault in the circuits between the FPDM and the fuel pump.

The P0420 is probably a bad after cat O2 sensor, but check to see if it recurs after clearing the code. If you are to change it and it still comes back, your cat may be failing and would need replaced.

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