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) IAC MOTOR OPERATION
NOTE: If the engine will not idle, maintain an engine speed between 800 and 1500 RPM.

Start the engine.

Allow the engine to idle.

With a scan tool, read the IAC Current.

Is the IAC Current below 146 mA?

Yes
1. Go To step 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) IAC MOTOR

Fig 1: Checking IAC Motor
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the IAC Motor harness connector.

Remove the IAC Motor.

NOTE: Inspect the IAC air passages for restrictions and damage to the IAC valve.

Measure the resistance across the IAC Motor pin terminals (component).

Is the resistance 9.7 +/- 1.0 ohms?

Yes
1. Go To step 3).
No
1. Replace the IAC Motor.
2. Perform POWERTRAIN VERIFICATION TEST .
3) (K961) IAC SIGNAL CIRCUIT OPEN

Fig 2: Checking IAC Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the C2 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 (K961) IAC Signal circuit from the IAC Motor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go To step 4).
No
1. Repair the open in the (K961) IAC Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
4) (K961) IAC SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: Checking IAC Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (K961) IAC Signal circuit in the IAC Motor harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (K961) IAC Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 5).
5) (K61) IAC CONTROL CIRCUIT OPEN

Fig 4: Checking IAC Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the (K61) IAC Control circuit from the IAC Motor 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 (K61) IAC Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
6) (K61) IAC CONTROL CIRCUIT SHORTED TO GROUND

Fig 5: Checking IAC Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (K61) IAC Control circuit in the IAC Motor harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (K61) IAC Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 7).
7) 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 .