Transmission Relay Always Off
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P0888 JEEP Possible Causes
- Faulty Transmission Control Relay
- Transmission Control Relay harness is open or shorted
- Transmission Control Relay circuit poor electrical connection
- Faulty Transmission Solenoid/Pressure Switch Assembly
How do I fix code P0888 JEEP?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Inadequate Transmission Control Relay Output voltage can also cause DTCs P0846, P0869, P0871, P0876 or P0988 to set. This does not indicate an internal transmission or solenoid TRS problem. Repairing the P0888 fault should also eliminate the related DTCs.
Cost of diagnosing the P0888 JEEP code
The cost of diagnosing the P0888 JEEP code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
This code is set when less than 3 volts are present at the Transmission Control Relay Output (switched battery) terminals at the Powertrain Control Module (PCM), when the PCM is energizing the relay.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0888 JEEP Description
The transmission control relay is used to supply power to the solenoid pack when the transmission is in normal operating mode. When the relay is off, no power is supplied to the solenoid pack and the transmission is in Limp-in mode. The relay output is fed back to the Powertrain Control Module (PCM). It is referred to as the Transmission Control Relay Output circuit or switched battery.
After a controller reset (ignition key turned to the run position or after cranking engine), the controller energizes the relay. Prior to this the PCM verifies that the contacts are open by checking for no voltage at the switched battery terminals. After the relay is energized, the PCM monitors the terminals to verify that the voltage is greater than 3 volts.