P0653-SENSOR REFERENCE VOLTAGE 2 CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes the Auxiliary 5-volt Supply circuit voltage is too high. One Trip Fault. ETC light is flashing.

Possible Causes

(F856) AUXILIARY 5-VOLT SUPPLY SHORTED TO BATTERY VOLTAGE

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1. ACTIVE DTC

Ignition on, engine not running.
With a scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

Go To 2

No

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2. (F856) AUXILIARY 5-VOLT SUPPLY SHORTED TO BATTERY VOLTAGE

Turn the ignition off.
Disconnect the C1 PCM harness connector.
Disconnect all the Sensors that share the (F856) Auxiliary 5-volt Supply circuit.

NOTE: Improperly installed aftermarket accessories can cause this DTC to set. Check for wiring added by customer.

Ignition on, engine not running.
Measure the voltage on the (F856) Auxiliary 5-volt Supply circuit at the CMP Sensor harness connector.

Is the voltage above 0 volts?

Yes

Repair the short to battery voltage in the (F856) Auxiliary 5-volt Supply circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

Go To 3

3. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)