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) CHECK TO SEE IF DTC P0890 IS PRESENT
With the scan tool, Check the STARTS SINCE SET counter for P0890.

NOTE: This counter only applies to the last DTC set.

Is the "Starts Since Set" counter set at 0?

Yes
1. Go To step 2).
No
1. Go To step 4).
2) PRESSURE SWITCH SENSE CIRCUITS SHORT TO VOLTAGE

Fig 1: Checking Pressure Switch Sense Circuits for Short to Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off to the lock position.

Disconnect the PCM C4 harness connector and connect Miller tool #8815.

Disconnect the Transmission Solenoid/TRS Assembly harness connector.

Remove the Transmission Control Relay.

NOTE: Note: Check connectors - Clean/repair as necessary.

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 tool #8815 to perform diagnosis.

Connect a jumper wire between the Fused B+ circuit and the Transmission Control Relay Output circuit in the Transmission Control Relay connector.

Ignition on, engine not running.

Measure the voltage of the (T147) 2C, (T48) 4C, (T50) LR, (T9) OD, and (T29) UD Pressure Switch Sense circuits in Miller tool #8815.

Is the voltage above 0.5 volt on any of the measured circuits?

Yes
1. Repair the (T147) 2C, (T48) 4C, (T50) LR, (T9) OD, and/or (T29) UD Pressure Switch Sense circuit(s) for a short to voltage.
2. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 .
No
1. Go To step 3).
3) TRANSMISSION SOLENOID/TRS ASSEMBLY

Fig 2: Checking Pressure Switch Sense Circuits for Short to Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Remove the jumper wire.

NOTE: Do not reinstall the Transmission Relay.

Reconnect the Transmission Solenoid/TRS Assembly harness connector.

Ignition on, engine not running.

Measure the voltage of the (T147) 2C, (T48) 4C, (T50) LR, (T9) OD, and (T29) UD Pressure Switch Sense circuits in Miller tool #8815.

Is the voltage above 0.5 volts on any of the sense circuits?

Yes
1. Replace the Transmission Solenoid/TRS Assembly.
2. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 .
No
1. Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM per the Service Information. With the scan tool, perform QUICK LEARN.
2. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 .
4) INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle the wires while checking for shorted and open circuits.

With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.

Where there any problems found?

Yes
1. Repair as necessary.
2. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 .
No
1. Test Complete.