Diagnostic Test

WARNING: This page is about a different car, the 2006 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) TEST FOR INTERMITTENT CONDITION
Turn the ignition on.

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.

With the scan tool, select ECU view.

NOTE: A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

Does the scan tool display a red X next to the module?

Yes
1. Go To step 2).
No
1. The no response condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.
2) (Z104) GROUND CIRCUIT OPEN

Fig 1: Checking Ground Circuit
Courtesy of DAIMLERCHRYSLER CORP.

WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Disconnect the Occupant Restraint Controller Module C2 harness connector.

Connect the appropriate Load Tool ACM Adapter to the ORC connector.

Using a 12-volt test light connected to 12-volts, check the (Z104) ground circuit.

Does the test light illuminate brightly?

Yes
1. Go To step 3).
No
1. Repair the (Z104) ground circuit for an open.
2. Perform SUPPLEMENTAL RESTRAINTS VERIFICATION TEST .
3) (F100) FUSED RUN RELAY OUTPUT CIRCUIT OPEN OR SHORTED

Fig 2: Checking Fused Run Relay Output Circuit
Courtesy of DAIMLERCHRYSLER CORP.

NOTE: Check the FCM for any ignition related DTCs before proceeding. If set (Refer to ELECTRICAL/IGNITION CONTROL - DIAGNOSIS AND TESTING) .

WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

Using a 12-volt test light connected to ground, check the (F100) Fused Run Relay Output circuit.

Does the test light illuminate brightly?

Yes
1. Go To step 4).
No
1. Repair the (F100) Fused Run Relay Output circuit for an open or short.
2. Perform SUPPLEMENTAL RESTRAINTS VERIFICATION TEST .
4) (F20) FUSED IGNITION SWITCH OUTPUT (RUN/START) CIRCUIT OPEN OR SHORTED

Fig 3: Checking Fused Ignition Switch Output (Run/Start) Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Using a 12-volt test light connected to ground, check the (F20) Fused Ignition Switch Output (RUN/START) circuit.

Does the test light illuminate brightly?

Yes
1. Go To step 5).
No
1. Repair the (F20) Fused Ignition Switch Output (RUN/START) circuit for an open or short.
2. Perform SUPPLEMENTAL RESTRAINTS VERIFICATION TEST .
5) (D55) AND (D54) CAN B BUS CIRCUITS OPEN

Fig 4: Checking CAN B BUS Circuits
Courtesy of DAIMLERCHRYSLER CORP.

WARNING: If the Occupant Restraint Controller is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and personal injury or death.

NOTE: One open circuit will not cause this condition.

Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.

Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.

Is there any voltage present on either circuit?

Yes
1. Replace the Occupant Restraint Controller Module in accordance with the service information.
2. Perform SUPPLEMENTAL RESTRAINTS VERIFICATION TEST .
No
1. Repair the (D55) and (D54) CAN B Bus circuits for an open. Inspect the connector for damage.
2. Perform SUPPLEMENTAL RESTRAINTS VERIFICATION TEST .