Ignition System - Electrical Diagnostics Jeep Grand Cherokee WK

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Scheme 1

Additional Wiring

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

Monitor Conditions

1. When Monitored: Anytime the ignition input is compared against the CAN B Bus ignition status message.

Set Conditions

1. Set Condition: The Front Control Module will set this DTC if the CAN bus message and the hardwired ignition circuit do not match.

Possible Causes

Scheme 2

Scheme 3

1. 1) CHECK FOR ACTIVE DTC NOTE: If B2104 or B2105 are active, perform those tests first before proceeding. NOTE: Check the Junction Block Fuse #24. An open fuse can cause this DTC to set. If open refer to the wiring diagrams to help isolate a possible shorted circuit. With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 10 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Using the wiring diagram/schematic as a guide, visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) (F942) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN Turn the ignition off. Disconnect the IPM C2 connector. Turn the ignition on. Measure the voltage of the (F942) Fused Ignition Switch Output circuit in the IPM C2 connector. Is the voltage above 10.0 volts? Yes Go to step 3) . No Repair the (F942) Fused Ignition Switch Output circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
3. 3) (F942) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN Turn the ignition off. Remove the FCM from the Integrated Power Module. NOTE: Reconnect the IPM C2 connector. Turn the ignition on. Measure the voltage of the (F942) Fused Ignition Switch Output circuit in the Front Control IPM connector. Is the voltage above 10.0 volts? Yes Replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Replace the Integrated Power Module in accordance with service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

Refer to DIAGNOSIS AND TESTING for the diagnostic test procedure.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

Refer to DIAGNOSIS AND TESTING for the diagnostic test procedure.

Scheme 4

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module will set this DTC within 500ms if the (P305) Accessory Delay Relay Control circuit is open or shorted to ground.

Scheme 5

Scheme 6

1. 1) CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) RUN/ACCESSORY DELAY RELAY Turn the ignition off. Install a substitute relay in place of the original Run/Accessory Delay Relay. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active FCM DTC's. Does the scan tool display this DTC as active? Yes Go to step 3) . No Replace the original Run/Accessory Delay Relay. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
3. 3) (P305) ACCESSORY DELAY RELAY CONTROL CIRCUIT OPEN Turn the ignition off. Remove the FCM from the Integrated Power Module. Remove the Run/Accessory Delay Relay from the Junction Block. Measure the resistance of the (P305) Accessory Delay Relay Control circuit from the Front Control Module IPM connector to the Relay connector. Is the resistance below 10.0 ohms? Yes Go to step 4) . No Repair the (P305) Accessory Delay Relay Control circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
4. 4) (P305) ACCESSORY DELAY RELAY CONTROL CIRCUIT SHORTED TO GROUND Measure the resistance between ground and the (P305) Accessory Delay Relay Control circuit at the relay cavity (85). Is the resistance below 100.0 ohms? Yes Repair the (P305) Accessory Delay Relay Control circuit for a short to ground. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module will set this DTC within 500ms if the (P305) Accessory Delay Relay Control circuit is shorted to voltage.

Scheme 7

1. 1) CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) RUN/ACCESSORY DELAY RELAY Turn the ignition off. Install a substitute relay in place of the original Run/Accessory Delay Relay. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active FCM DTC's. Does the scan tool display this DTC as active? Yes Go to step 3) . No Replace the original Run/Accessory Delay Relay. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
3. 3) (P305) ACCESSORY DELAY RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Remove the FCM from the Integrated Power Module. Remove the Run/Accessory Delay Relay from the Junction Block. Turn the ignition on. Measure the voltage of the (P305) Accessory Delay Relay Control circuit at the relay connector (cavity 85). Is there any voltage present? Yes Repair the (P305) Accessory Delay Relay Control circuit for a short to voltage. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module will set this DTC within 500ms if the (P305) Accessory Delay Relay Control circuit is open.

Diagnostic Test

1. 1) CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) RUN/ACCESSORY DELAY RELAY Turn the ignition off. Install a substitute relay in place of the original Run/Accessory Delay Relay. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds. With the scan tool, read the active FCM DTC's. Does the scan tool display this DTC as active? Yes Go to step 3) . No Replace the original Run/Accessory Delay Relay. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
3. 3) (P305) ACCESSORY DELAY RELAY CONTROL CIRCUIT OPEN Turn the ignition off. Remove the FCM from the Integrated Power Module. Remove the Run/Accessory Delay Relay from the Junction Block. Measure the resistance of the (P305) Accessory Delay Relay Control circuit from the FCM-IPM connector to the relay connector. Is the resistance below 10.0 ohms? No Repair the (P305) Accessory Delay Relay Control circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . Yes Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

Refer to DIAGNOSIS AND TESTING for the diagnostic test procedure.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

Refer to DIAGNOSIS AND TESTING for the diagnostic test procedure.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module is not configured correctly setting a false DTC that does not apply to this vehicle.

1. 1) CHECK FOR ACTIVE DTC AND DETERMINE FCM CONFIGURATION With the scan tool, read the active DTC's. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes With the scan tool enter program network configuration and program the FCM to the vehicle configuration, erase DTC's and retest. No If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Erase the stored DTCs.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on.

1. Set Condition: The Front Control Module will set this DTC within 500ms if the (F1) fused ignition switch output circuit voltage is less than the expected value.

Theory Of Operation

The (F942) Fused Ignition Switch Output circuit supplies the FCM with battery power. The FCM processes the input and sends it out as the (F1) Fused Ignition Switch Output circuit to the Shift Lever assembly (3.7L) or the PCM (except 3.7L).

Scheme 8

Scheme 9

Scheme 10

Scheme 11

1. 1) CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 10 seconds. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Using the wiring diagram/schematic as a guide, visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) DETERMINE ENGINE SIZE Is this vehicle equipped with a 3.7L engine? Yes Go to step 3) . No Go to step 6) .
3. 3) SHIFT LEVER ASSEMBLY With the scan tool, erase the FCM DTC's. Turn the ignition off. Disconnect the Shift Lever Assembly harness connector. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 10 seconds. With the scan tool, read the active FCM DTC's. Does the scan tool display this DTC as active? Yes Go to step 4) . No Replace the Shift Lever Assembly in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
4. 4) (F1) FUSED IGNITION SWITCH OUTPUT WIRE SHORT TO GROUND Turn the ignition off. Disconnect the Integrated Power Module C1 harness connector. Measure the resistance between ground and the (F1) Fused Ignition Switch Output circuit in the IPM C1 connector. Is the resistance below 1000.0 ohms? No Go to step 5) . Yes Repair the (F1) Fused Ignition Switch Output circuit for a short to ground. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
5. 5) INTEGRATED POWER MODULE SHORTED Remove the FCM from the Integrated Power Module. Measure the resistance between ground and the (F1) Fused Ignition Switch Output circuit in the Front Control Module IPM connector. Is the resistance below 1000.0 ohms? Yes Replace the Integrated Power Module in accordance with service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
6. 6) POWERTRAIN CONTROL MODULE With the scan tool, erase the FCM DTC's. Turn the ignition off. Disconnect the Powertrain Control Module C1 connector. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 10 seconds. With the scan tool, read the active FCM DTC's. Does the scan tool display this DTC as active? Yes Go to step 7) . No Replace the Powertrain Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
7. 7) (F1) FUSED IGNITION SWITCH OUTPUT WIRE SHORT TO GROUND Turn the ignition off. Disconnect the Integrated Power Module C1 harness connector. Measure the resistance between ground and the (F1) Fused Ignition Switch Output circuit in the IPM C1 connector. Is the resistance below 1000.0 ohms? No Go to step 5) . Yes Repair the (F1) Fused Ignition Switch Output circuit for a short to ground. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

1. When Monitored: With the ignition on or off and with the FCM awake.

1. Set Condition: The Front Control Module will set this DTC within 2 seconds if the ignition unlock run/start circuit voltage is not what the expected value should be.

The (F942) Fused Ignition Switch Output circuit supplies the FCM with battery power. The FCM processes the input and sends it out as the (F1) Fused Ignition Switch Output circuit to the Shift Lever assembly (3.7L) or the PCM (except 3.7L).

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

1. 1) CHECK FOR ACTIVE DTC With the scan tool, read the active DTC's. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 10 seconds then turn the ignition off. With the scan tool, read the active DTC's. Does the scan tool display this DTC as active? Yes Go to step 2) . No If the DTC is stored, check for an intermittent condition. Using the wiring diagram/schematic as a guide, visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. 2) DETERMINE ENGINE SIZE Is this vehicle equipped with a 3.7L engine? Yes Go to step 3) . No Go to step 6) .
3. 3) (F1) FUSED IGNITION SWITCH OUTPUT (RUN START) CIRCUIT SHORTED TO VOLTAGE Disconnect the Shift Lever Assembly harness connector. Cycle the ignition switch from off to on then back to off. NOTE: The ignition switch must be in the off position when performing the following step. Using a 12-volt test light connected to ground, check the (F1) Fused Ignition Switch Output (Run Start) circuit. Does the test light illuminate brightly? Yes Repair the (F1) Fused Ignition Switch Output (Run Start) circuit for a short to voltage. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Go to step 4) .
4. 4) SHIFT LEVER ASSEMBLY Turn the ignition on. With the test light still connected from the previous step, check the (F1) Fused Ignition Switch Output (Run Start) circuit. Does the test light illuminate brightly? Yes Replace the Shift Lever Assembly in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Go to step 5) .
5. 5) (F1) FUSED IGNITION SWITCH OUTPUT (RUN START) CIRCUIT OPEN Turn the ignition off. Remove the FCM from the Integrated Power Module. Measure the resistance of the (F1) Fused Ignition Switch Output (Run Start) circuit between the Shift Lever Assembly and the FCM-IPM connector. Is the resistance below 5.0 ohms? Yes Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Repair the (F1) Fused Ignition Switch Output (Run Start) circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .
6. 6) (F1) FUSED IGNITION SWITCH OUTPUT (RUN START) CIRCUIT SHORTED TO VOLTAGE Disconnect the Powertrain Control Module C1 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. Cycle the ignition switch from off to on then back to off. NOTE: The ignition switch must be in the off position when performing the following step. Using a 12-volt test light connected to ground, check the (F1) Fused Ignition Switch Output (Run Start) circuit. Does the test light illuminate brightly? Yes Repair the (F1) Fused Ignition Switch Output (Run Start) circuit for a short to voltage. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Go to step 7) .
7. 7) POWERTRAIN CONTROL MODULE Turn the ignition on. With the test light still connected from the previous step, check the (F1) Fused Ignition Switch Output (Run Start) circuit. 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. Does the test light illuminate brightly? Yes Replace the Powertrain Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Go to step 8) .
8. 8) (F1) FUSED IGNITION SWITCH OUTPUT (RUN START) CIRCUIT OPEN Turn the ignition off. Remove the FCM from the Integrated Power Module. 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. Measure the resistance of the (F1) Fused Ignition Switch Output (Run Start) circuit between the Powertrain Control Module C1 connector and the FCM-IPM connector. Is the resistance below 5.0 ohms? Yes Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module in accordance with the service information. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) . No Repair the (F1) Fused Ignition Switch Output (Run Start) circuit for an open. Perform «BODY VERIFICATION TEST - VER 1»(/jeep/grand-cherokee/wk-2004-2010/remont/communication-devices/#electronic-control-modules-electrical-diagnostics) .

See also:
• BODY VERIFICATION TEST - VER 1
• DIAGNOSIS AND TESTING
• B2100