P0653

SYMPTOM
P0653-SENSOR REFERENCE VOLTAGE 2 CIRCUIT HIGH

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. Scan Tool Testing and Procedures

DIAGNOSTIC TEST
1. ACTIVE DTC





Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Yes>> Go To 2
No>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5. Powertrain Verification Test - Ver 5

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





Turn the ignition off.
Disconnect the PCM harness connectors.
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 5.2 volts?
Yes>> Repair the short to battery voltage in the (F856) Auxiliary 5-volt Supply circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
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 (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Replace and program the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.