Test Procedure

FE1: DTCS P2531 AND P2535: CHECK FOR SELF-TEST DTCS
- Are DTCs P2531 or P2535 present during PCM or transaxle control module (TCM) self-test?
- Yes: For DTC P2531, GO to FE2.
  For DTC P2535, GO to FE6.
- No: GO to FE8.
FE2: DTC P2531: CHECK THE ISP-R PID
- Access the PCM and monitor the IGN_R PID.
- Key ON, engine OFF.
- Does the PID indicate YES (key in ISP-R position)?
- Yes: GO to FE8.
- No: GO to FE3.
FE3: CHECK FUSES
- Key in OFF position.
- Inspect all the ignition switch related fuses.
- Are the ignition switch fuses OK?
- Yes: GO to FE4.
- No: INSTALL a new fuse as necessary. GO to FE5.

FE4: CHECK THE IGNITION SWITCH AND HARNESS FOR AN OPEN

PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
ISP-R - Pin B22	Negative terminal

Is the voltage greater than 10.5 V?

Yes: GO to FE9.
No: CHECK for a damaged ignition switch.
REFER to the appropriate Component Testing article .

If the ignition switch is OK, REPAIR the open circuit.

CLEAR the DTCs. REPEAT the self-test.

FE5: CHECK THE ISP-R CIRCUIT FOR A SHORT TO GND IN THE HARNESS

Ignition Switch connector disconnected.
PCM connector disconnected.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
ISP-R - Pin B22	Negative terminal

Is the resistance greater than 10K ohms?

Yes: CHECK the ignition switch for a short to ground. If OK, GO to FE9.
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

FE6: DTC P2535: CHECK THE ISP-R/S PID
- Key ON, engine OFF.
- Does the engine start with the ignition key in ON position?
- Yes: GO to FE7.
- No: GO to FE8.

FE7: CHECK THE ISP-R/S CIRCUIT FOR A SHORT TO VOLTAGE

Key in OFF position.
PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
ISP-R/S - Pin B21	Negative terminal

Is the voltage less than 1 V?

Yes: GO to FE9.
No: CHECK for a damaged ignition switch.
REFER to the appropriate Component Testing article .

If the ignition switch is OK, REPAIR the circuit.

CLEAR the DTCs. REPEAT the self-test.

FE8: CHECK THE ISP-R AND ISP-R/S CIRCUITS FOR INTERMITTENT CONCERNS
- Key ON, engine OFF.
- Access the PCM and monitor the IGN R and IGN R/S PIDs.
- Turn the key to the ON and START positions, while observing the related ignition PID.
  Carefully wiggle all accessible wiring and connectors associated with the circuit and look for a change in the PID state.
- Is a concern present during the wiggle test?
- Yes: REPAIR as necessary.
  CLEAR the DTCs. REPEAT the self-test.
- No: GO to PINPOINT TEST Z .
FE9: CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
  - pushed out pins
  - corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new PCM.
  REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.