3.(Z42) GROUND CIRCUIT OPEN
Turn the ignition off.
Using a 12-volt test light connected to the 12-volts, probe the (Z42)
Ground circuit in the MDS Solenoid No.7 harness connector.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open in the (Z42) Ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
4.(K454) MDS SOLENOID NO.7 CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C3 PCM harness connector.
Measure the resistance between ground and the (K454) MDS Solenoid
No.7 Control circuit in the MDS Solenoid No.7 harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K454) MDS Solenoid
No.7 Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
P1603-PCM INTERNAL DUAL-PORT RAM COMMUNICATION FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Offf,
Run, Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
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?
Ye s>>
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)
P1604-PCM INTERNAL DUAL-PORT RAM READ/WRITE INTEGRITY FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run,
Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
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?
Ye s>>
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)
P1607-PCM INTERNAL SHUTDOWN TIMER SLOW RATIONALITY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run,
Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
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?
Ye s>>
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)
When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes the Primary 5-volt Supply circuit voltage is varying too much too quickly. One Trip
Fault. ETC light is flashing.
Possible Causes
(F855) PRIMARY 5-VOLT SUPPLY SHORTED TO GROUND
(F855) PRIMARY 5-VOLT SUPPLY SHORTED TO BATTERY VOLTAGE
(F855) PRIMARY 5-VOLT SUPPLY CIRCUIT OPEN
5-VOLT SENSOR
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, read DTCs.
Is the DTC active at this time?
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.(F855) PRIMARY 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Disconnect all the Sensors that share the (F855) Primary 5-volt Supply
circuit.
NOTE: This code can be caused by the improper installation of
after market accessories that may be causing excessive noise on
the (F855) 5-volt Supply circuit.
Measure the resistance between ground and the (F855) Primary 5-volt
Supply circuit in the CKP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) Primary 5-volt Sup-
ply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes the Auxiliary 5-volt Supply circuit voltage is varying too much too quickly. One Trip
Fault. ETC light is flashing.
Possible Causes
(F856) AUXILIARY 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F856) AUXILIARY 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY VOLTAGE
(F856) AUXILIARY 5-VOLT SUPPLY CIRCUIT OPEN
5-VOLT SENSOR
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, read DTCs.
Is the DTC active at this time?
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.(F856) AUXILIARY 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Disconnect all the Sensors that share the (F856) Auxiliary 5-volt Supply
circuit.
NOTE: This code can be caused by the improper installation of
after market accessories that may be causing excessive noise on
the (F856) 5-volt Supply circuit.
Measure the resistance between ground and the (F856) Auxiliary 5-volt
Supply circuit at the CMP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F856) Auxiliary 5-volt
Supply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
P1897-LEVEL 1 RPM BUS UNLOCK
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Engine running.
Set Condition:
When the PCM recognizes an internal failure to communicate with the FCM or the CMP and CKP Sensor
count periods are too short. One trip fault. ETC light is flashing.
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 on and the ETC Motor is not in Limp Home mode.
Set Condition:
When the PCM detects an internal error or a short between the ETC Motor - and ETC Motor + circuits in the
ETC Motor Driver. One trip fault. ETC light is flashing.
Possible Causes
THROTTLE PLATE / BORE INSPECTION
(K447) ETC POSITIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
(K448) ETC NEGATIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
(K447) ETC POSITIVE CIRCUIT SHORTED TO THE (K448) ETC NEGATIVE CIRCUIT
(K447) ETC POSITIVE CIRCUIT OPEN
(K447) ETC POSITIVE CIRCUIT SHORTED TO GROUND
(K448) ETC NEGATIVE CIRCUIT OPEN
(K448) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
LOW BATTERY VOLTAGE
ETC MOTOR/THROTTLE BODY
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.
NOTE: If the P2100 is intermittent, it is possible that the controller is overheating in extreme hot tempera-
tures, and this is considered a normal protection operation. No repair is necessary.
NOTE: Low battery voltage can also cause excessive current draw, in very hot and very cold ambient tem-
peratures. Make sure the battery can pass a load test before continuing.
With a scan tool, read DTCs.
Look closely at the temperatures at which this DTC set.
Is the DTC active at this time?
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.THROTTLE PLATE INSPECTION
Turn the ignition off.
Remove the Air Cleaner Assembly from the Throttle Body.
Check for any signs of a foreign material (ice or dirt) on the Throttle Plateor in the bore causing the Throttle Plate
to stick.
Were any signs of foreign material or scoring of the throttle plate or bore found?
Ye s>>
Remove the debris if possible or replace the Throttle Body Assembly. Disconnect the Battery when
replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC
RELEARN function.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3