HW31 - HW40

HW31 - Check PF Circuit For Shorts To PWR GND

- Install breakout box, leave PCM disconnected.
- Disconnect scan tool from DLC.
- Measure resistance between PCM test pin 11 and PCM test pins 24 and 103.

Are both resistances greater than 10,000 ohms?

YES REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test.
NO REPAIR short circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.

HW32 - Check Purge Flow Sensor Circuit For Intermittent VPWR Open Or PWR GND Short

- Key on, engine off.
- Access EVAPPF PID.
- Observe EVAPPF PID for an indication of a fault while performing the following:
- Lightly tap on PF sensor; wiggle PF sensor connector and harness between sensor and PCM. A fault is indicated by a sudden change in EVAPPF PID voltage (less than 0.14 volt).

Is a fault indicated?

YES ISOLATE fault and REPAIR as necessary. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.
NO Unable to duplicate or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data:

PF PID and a list of Possible causes. Z - Intermittent

HW33 - DTC P1445: Check PF Sensor High Voltage To PCM

Continuous Memory Diagnostic Trouble Code (DTC) P1445 indicates that Self-Test has detected a PF sensor circuit input above the maximum. Possible causes:
- PF shorted to VPWR.
- PF open circuit.
- PWR GND open circuit.
- Damaged purge flow (PF) sensor.
- Damaged PCM.

- Disconnect PF sensor.
- Check for loose pins or broken wires by pulling moderately on the PF and PWR GND circuits at PF sensor harness connector.
- Repair as necessary.
- Reconnect PF sensor.
- Connect scan tool.
- Key on, engine off.

NOTE: PF sensor input to the PCM range is 0.40 to 4.80 volts.

- Access EVAPPF PID.
- Key off.

Was EVAPPF PID voltage greater than 4.80 volts?

YES GO to HW34.
NO Fault is an intermittent DTC P1445. GO to HW39 .

HW34 - Check VPWR Resistance For Short To PF Circuit In PF Sensor

- Key off.
- Disconnect PF sensor.
- Allow the vehicle and PF sensor to cool down or warm up to a room temperature 13°C to 27°C (550 F to 80°F) before taking a resistance measurement on the PF sensor. This can take 15 to 20 minutes.
- Measure resistance between VPWR and PF pins on the PF sensor.

Is resistance between 40 and 230 ohms?

YES GO to HW35.
NO REPLACE damaged PF sensor. RESTORE vehicle. GO to HW42. HW41 - HW43

HW35 - Check PF Sensor Voltage In Put To PCM

- Key on, engine off.
- Measure PF circuit voltage at PF sensor harness connector to battery negative post.
- Key off.

Was voltage greater than 10.5 volts?

YES GO to HW36.
NO GO to HW37.

HW36 - Check PF Circuit For Short To VPWR In Harness

- Install breakout box, leave PCM disconnected.
- Key on, engine off.
- Measure resistance between PCM test pin 11 and PCM test pins 24 or 103.

Is the voltage greater than 10.5 volts?

YES REPAIR short circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.
NO REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test.

HW37 - Check PF Circuit For Open In Harness

- Install breakout box, leave PCM disconnected.
- Measure resistance of PF circuit between PCM test pin 11 and PF sensor harness connector.

Is the resistance less than 5.0 ohms?

YES GO to HW38.
NO REPAIR open circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.

HW38 - Check PWR GND Circuit For Open In Harness

- Measure resistance of PWR GND circuit between PCM test pin 24 or 103 and PF sensor harness connector.

Is the resistance less than 5.0 ohms?

YES REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test.
NO REPAIR open circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.

HW39 - Check Purge Flow Sensor Circuit For Intermittent PF Open Or VPWR Short

- Key on, engine off.
- Access EVAPPF PID.
- Observe EVAPPF PID for an indication of a fault while performing the following:
- Lightly tap on PF sensor; wiggle PF sensor connector and harness between sensor and PCM. A fault is indicated by a sudden change in EVAPPF PID voltage (greater than 4.80 volts).

Is a fault indicated?

YES ISOLATE fault and REPAIR as necessary. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.
NO UNABLE to duplicate or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data:

- PF PID and a list of Possible causes.

HW4O - DTC P0443: Inspect EVAP Canister Purge Valve Circuit For Intermittent Failure

Continuous Memory Diagnostic Trouble Code (DTC) P0443 may indicate an EVAP canister purge valve circuit failure. Possible causes:
- Damaged EVAP canister purge valve.
- EVAP CANISTER PURGE or VPWR circuit open.

- Rerun KOEO, KOER Self-Tests and retrieve Continuous Memory DTCs.

Is DTC P0443 present in Continuous Memory Self-Test only?

YES GO to HW41. HW41 - HW43
NO GO to HW1. HW1 - HW10