| P025A |
P027A |
Missing or invalid PWM Command signal from PCM |
- PCM to FPCM Command Signal open
- PCM to FPCM Command Signal shorted low or high
- Invalid PWM signal - frequency out of range
- FPCM
- PCM
|
- FPCM defaults the output to the Fuel Pump to 80% duty cycle
NOTE:
It is not uncommon for the P025A DTC to set erroneously for several other failure modes
|
| P025B |
P027B |
Output driver over temp |
- FPCM Output partially shorted to ground
- Faulty Fuel Pump (high mechanical resistance)
- Faulty FPCM internal driver
|
- PCM sets fault, waits a calibrated period and commands a safe duty cycle
- FPCM output to Fuel Pump to 50% duty cycle for a calibrated period. If over temp continues, shut down output driver.
|
| P025C |
P027C |
System under voltage - Fuel Pump Relay output voltage to FPCM is below a calibrated threshold (approximately 6.0 volts) |
- High resistance in the Fuel Pump Relay output circuit
- FPCM
|
- PCM requests 100% Fuel Pump operation
- FPCM defaults the output to the Fuel Pump to 80% duty cycle
|
| P025D |
P027D |
System over voltage - Fuel Pump Relay output voltage to FPCM is above a calibrated threshold (approximately 16.0 volts) |
- Charging system issue
|
- PCM applies over voltage strategy
- FPCM reacts to PCM input command
|
| P0628 |
P2633 |
FPCM output to Fuel Pump shorted to ground |
- Fuel Pump PWM Control circuit shorted to ground
|
- PCM reduces PWM duty cycle until issue clears
- FPCM reacts to PCM input command
|
| P0629 |
P2634 |
FPCM output to Fuel Pump shorted to voltage |
- Fuel Pump PWM Control circuit shorted to voltage
|
- FPCM output to Fuel Pump to 50% duty cycle for a calibrated period. If condition continues, shut down output driver.
|
| P062A |
P062A |
Actual fuel pressure is above or below the desired fuel pressure by more than a calibrated threshold.
- Fixed pressure system - 5.8 psi above or 14.5 psi below
- Variable pressure system - 10.9 psi above or below
|
- No fuel in the Fuel Tank
- Fuel supply tube broken/leaking
- Fuel supply tube pinched/restricted
- FPCM defaulted to 80% due to another failure detected
- FPCM duty cycle output reduced due to another failure detected
- Faulty Fuel Pump
|
- PCM requests 100% Fuel Pump operation
- FPCM defaults the output to the Fuel Pump to 80% duty cycle
|
| P064A |
P26EA |
Current draw exceeds calibrated threshold |
- Fuel Pump PWM Control circuit shorted to voltage
- Faulty Fuel Pump - internal short or high mechanical resistance
|
- PCM reduces PWM duty cycle until issue clears
- FPCM reacts to PCM input command
|
| P1205 |
P120A |
FPCM Micro internal fault |
- Fuel Pump Control Module
|
- FPCM continues to run in normal mode - run Fuel Pump according to PCM command signal
|
| P1206 |
P120B |
FPCM output to Fuel Pump open circuit |
- Fuel Pump PWM Control circuit open
- Fuel Pump Return/Ground circuit open
- FPCM Ground circuit open
- FPCM
|
- PCM reduces PWM duty cycle until issue clears
- FPCM reacts to PCM input command
|
| U0109 |
U016C |
PCM Loss of Communication with FPCM |
- FPCM PWM Feedback circuit open
- FPCM PWM Feedback shorted low or high
- Fuel Pump Relay output circuit to FPCM open or shorted to ground
- FPCM Ground circuit open
- Fuel Pump PWM Control circuit shorted to ground
- FPCM
- PCM
|
- PCM requests 100% Fuel Pump operation
- FPCM defaults the output to the Fuel Pump to 80% duty cycle
|