Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go To step 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) (F42) ASD RELAY OUTPUT CIRCUIT

Fig 1: Checking ASD Relay Output Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the No.7 Fuel Injector harness connector.

Ignition on, engine not running.

With the scan tool, actuate the ASD Relay.

Using a 12-volt test light connected to ground, probe the (F42) ASD Relay Output circuit in the No.7 Fuel Injector harness connector.

Does the test light illuminate brightly?

Yes
1. Go To step 3).
No
1. Repair the excessive resistance or short to ground in the (F42) ASD Relay Output circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
3) FUEL INJECTOR

Fig 2: Checking Fuel Injector
Courtesy of DAIMLERCHRYSLER CORP.

Using a 12-volt test light connected to 12-volts, probe the (K26) Injector Control No.7 circuit.

With the scan tool, actuate the No.7 Fuel Injector.

What is the state of the test light during the actuation?

Brightly Blinking.
1. Replace the Fuel Injector.
2. Perform POWERTRAIN VERIFICATION TEST .
ON Constantly.
1. Go To step 4).
OFF Constantly.
1. Go To step 5).
4) (K26) INJECTOR CONTROL NO.7 CIRCUIT SHORTED TO GROUND

Fig 3: Checking Injector Control No. 7 Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C1 PCM harness connector.

Measure the resistance between ground and the (K26) Injector Control No.7 circuit in the Injector harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (K26) Injector Control No.7 circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 6).
5) (K26) INJECTOR CONTROL NO.7 CIRCUIT OPEN

Fig 4: Checking Injector Control No. 7 Circuit
Courtesy of DAIMLERCHRYSLER CORP.

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.

Measure the resistance of the (K26) Injector Control No.7 circuit from the Fuel Injector harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go To step 6).
No
1. Repair the open in the (K26) Injector Control No.7 circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
6) 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
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .