When Monitored:
At power-up and battery voltage greater than 11.5 volts.
Set Condition:
The PCM senses a short to ground or battery voltage on any of the four Idle AirControl (IAC) driver circuits
for 100 ms while the IAC motor is active.
Possible Causes
(K40) IAC #1 DRIVER CIRCUIT SHORTED TO (K60) #2, (K39) #3, OR (K59) #4 IAC DRIVER CIRCUITS
(K60) IAC #2 DRIVER CIRCUIT SHORTED TO (K39) IAC #3 OR (K59) IAC #4
(K39) IAC #3 DRIVER CIRCUIT SHORTED TO (K59) IAC #4 DRIVER CIRCUIT
IAC DRIVER CIRCUIT SHORTED TO VOLTAGE
IAC DRIVER CIRCUIT SHORTED TO GROUND
IAC MOTOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.IAC #1 DRIVER CIRCUIT SHORTED TO #2, #3, OR #4
Turn the ignition off.
Disconnect the IAC Motor harness connector.
Disconnect the C1 PCM harness connector.
NOTE: The following steps are checking for a short between the
IAC Driver circuits.
Measure the resistance between the (K40) IAC #1 Driver circuit and #2,
#3, #4 Driver circuits.
Istheresistancebelow100ohmsonanyoftheDrivers?
Ye s>>
Repair the short between the IAC Driver circuits.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
With the ignition on and battery voltage above 10.4 volts.
Set Condition:
The oil pressure sensor signal at PCM goes above 4.9 volts. One Trip Fault.
Possible Causes
OIL PRESSURE SENSOR
(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(G6) OIL PRESSURE SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.OIL PRESSURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the Oil Pressure Sensor voltage above 4.8 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.OIL PRESSURE SENSOR
Turn the ignition off.
Disconnect the Oil Pressure Sensor harness connector.
Ignition on, engine not running.
Connect a jumper wire between the (G60) Oil Pressure Signal circuit and (K900) Sensor ground circuit at the Sen-
sor harness connector.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the voltage below 1.0 volt?
Ye s>>
Replace the Oil Pressure Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
NOTE: Remove the jumper wire before continuing.
3.(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the PCM harness connectors.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (G6) Oil PressureSignal circuit.
Is the test light brightly illuminated?
Ye s>>
Repair the short to voltage in the (G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
P0601-PCM INTERNAL CONTROLLER FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
With the ignition on.
Set Condition:
Internal checksum for software failed, does not match calculated value. One Trip Fault, Three Good Trips to
clear.
Possible Causes
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM
NOTE: Diagnose any CMP or CKP Sensor faults before continuing. Check for intermittent loose CMP or CKP
connections.
The Powertrain Control Module is reporting internal errors, view repair to continue.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
With the ignition key on and the engine running.
Set Condition:
When the PCM tries to regulate the generator field with no result during monitoring.
Possible Causes
(K125) GEN FIELD SOURCE CIRCUIT OPEN
(K20) GEN FIELD CONTROL CIRCUIT OPEN
(K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND
GENERATOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GENERATOR FIELD PERFORMANCE
Ignition on, engine not running.
Record all DTCs and the related Freeze Frame data.
Turn the ignition off.
Disconnect the Generator harness connector.
Ignition on, engine not running.
Using a 12-volt test light connected to 12-volts, probe the (K20) Gen
Field Control circuit at the Generator harness connector.
With the scan tool, actuate the Generator Field Driver.
Does the test light blink?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Pro-
cedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.(K125) GEN FIELD SOURCE CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2 and C3 PCM harness connectors.
Carefully inspect all connectors for corrosion or spread terminals before
continuing.
Measure the resistance of the (K125) Generator Field Source circuit
from the Generator harness connector to the C3 PCM harness connec-
tor.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 3
No>>
Repair the open in the (K125) Gen Field Source circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
When Monitored:
Engine at operating temperature, Engine RPM above 608 rpm’s, and Vehicle Speed above 5 MPH.
Set Condition:
Reverse Gear Lockout Solenoid Control circuit is not in the expected statewhen requested to operate by the
PCM. Note: When Vehicle Speed is less then 5 MPH the PCM provides a ground forthe solenoid which ener-
gizes the solenoid. (Allowing Reverse).
Possible Causes
(A917) FUSED IGNITION SWITCH OUTPUT CIRCUIT
(K333) REVERSE LOCKOUT SOLENOID CONTROL CIRCUIT OPEN
(K333) REVERSE LOCKOUT SOLENOID CONTROL CIRCUIT SHORT TO GROUND
REVERSE LOCKOUT SOLENOID
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(A917) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN OR SHORT TO GROUND
Turn the ignition off.
Disconnect the Reverse Lockout Solenoid harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (A917) Fused
Ignition Switch Output circuit.
NOTE: The test light must be brightly lit. If the test light does not
light or is Dim repair the circuit for a open or high resistance cir-
cuit.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the open or short to ground in the (A917) Fused
Ignition Switch Output circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
When Monitored:
With the engine running, coolant greater than 170°F, open throttle, steady to slightly increasing vehicle speed
greater than 18 mph but less than 55 mph, with a light load on the engine, for aperiod no less than 5 minutes.
Set Condition:
The oxygen sensor signal voltage is switching from below 0.39 of a volt to above 0.6 of a volt and back fewer
times than required.
Possible Causes
EXHAUST LEAK
RESISTANCE IN THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT
RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
O2 SENSOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.EXHAUST LEAK
Start the engine.
Inspect the exhaust for leaks between the engine and the appropriate O2 Sensor.
Are there any exhaust leaks?
Ye s>>
Repair or replace the leaking exhaust parts as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.(K41) O2 SENSOR 1/1 SIGNAL CIRCUIT VOLTAGE DROP
Turn the ignition off.
Backprobe the (K41) O2 Sensor 1/1 Signal circuit at the 1/1 O2 Sensor harness connector and PCM harness con-
nector.
NOTE: Make sure the voltmeter leads are connected for positive polarity, meet the terminals in the connec-
tor, and that there is good terminal to wire connection.
NOTE: Make sure the voltmeter leads are connected for positive polarity
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 of a volt?
Ye s>>
Go To 4
No>>
Repair the excessive resistance on the (K41) O2 Sensor 1/1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
With the engine running, coolant greater than 170°F, open throttle, steady to slightly increasing vehicle speed
greater than 18 mph but less than 55 mph, with a light load on the engine, for aperiod no less than 5 minutes.
Set Condition:
The oxygen sensor signal voltage is switching from below 0.39 of a volt to above 0.6 of a volt and back fewer
times than required.
Possible Causes
EXHAUST LEAK
RESISTANCE IN THE (K43) O2 SENSOR 2/1 SIGNAL CIRCUIT
RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
O2 SENSOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.EXHAUST LEAK
Start the engine.
Inspect the exhaust for leaks between the engine and the appropriate O2 Sensor.
Are there any exhaust leaks?
Ye s>>
Repair or replace the leaking exhaust parts as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.(K43) O2 SENSOR 2/1 SIGNAL CIRCUIT VOLTAGE DROP
Turn the ignition off.
Backprobe the (K43) O2 Sensor 2/1 Signal circuit at the 2/1 O2 Sensor harness connector and PCM harness con-
nector.
NOTE: Make sure the voltmeter leads are connected for positive polarity, meet the terminals in the connec-
tor, and that there is good terminal to wire connection.
NOTE: Make sure the voltmeter leads are connected for positive polarity
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 of a volt?
Ye s>>
Go To 4
No>>
Repair the excessive resistance on the (K43) O2 Sensor 2/1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts. TIPM requesting A/C Clutch operation.
Set Condition:
An overcurrent condition is detected in the A/C Clutch control output circuit. One Trip Fault. Three good trips
to turn off the MIL.
Possible Causes
TERMINAL DAMAGE OR CORROSION
A/C CLUTCH GROUND HIGH RESISTANCE
(C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT HIGH RESISTANCE
A/C COMPRESSOR CLUTCH
TIPM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.A/C CLUTCH OPERATION
Ignition on, engine not running.
With a scan tool in the TIPM Actuators, actuate the A/C Clutch.
Is the A/C Clutch actuating?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.VISUAL AND PHYSICAL CONNECTOR AND TERMINAL INSPECTION
Turn the ignition off.
Disconnect the TIPM C9 harness connector.
Disconnect the A/C Clutch harness connector.
Inspect the terminal and connector condition. Check for signs of corrosion build up or damage the would compro-
mise the terminal to controller pin connector.
NOTE: Make sure that all in-line connectors are inspected for corrosion and/or damage.
Visually inspect the wiring harness. Look for any chafed, pierced, pinched or partially broken wires hidden in the
wire insulation.
Were any of the above conditions found?
Ye s>>
Repair or replace as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3