P1671

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Change Oil Soon indicator is powered through a 10 Amp fuse in the fuse block. The PCM turns on indicator by supplying a path to ground through the PCM.

Conditions for Setting the DTC

A PCM controlled lamp on at all times most likely indicates that a condition is present which requires the attention of the vehicle operator.

Check for the following conditions:

^ Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection

^ Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM and turn the ignition on. Observe a voltmeter connected to the affected PCM output circuit while moving connectors and wiring harnesses related to the PCM output circuit. A change in voltage will indicate the location of the fault.

Action Taken When the DTC Sets

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).

^ The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

^ DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids

A PCM controlled lamp on at all times most likely indicates that a condition is present which requires the attention of the vehicle operator.

Check for the following conditions:

^ Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals. and poor terminal to wire connection.

^ Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM and turn the ignition on. Observe a voltmeter connected to the affected PCM output circuit while moving connectors and wiring harnesses related to the PCM output circuit. A change in voltage will indicate the location of the fault.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

3. Normally, ignition feed voltage should be present on the output control circuit with the PCM disconnected and the ignition turned on.

4. Checks for a shorted component or a short to B+ on the output control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.

5. Checks for a short to voltage on the lamp control circuit.

16. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to PCM Replacement/programming.