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P0740 Fault in 2004 Jeep Grand Cherokee 4X4 with 545RFE Transmission - No Overdrive and CEL Activation

Model: 2004 Grand Cherokee Fault Code: P0740 Posted: 2016-02-29 11:48

Hello, I'm new to this forum and seeking help with a recurring issue on my 2004 Jeep Grand Cherokee 4X4 (4.7L H/O engine, 545RFE transmission). The vehicle will not shift into overdrive and consistently triggers the P0740 Diagnostic Trouble Code (DTC), which illuminates the Check Engine Light (CEL). I recently replaced the torque converter solenoid block with a new OEM part and also installed a TRANSGO reprogramming kit. While these steps resolved some issues, the vehicle still fails to enter overdrive. After driving 20–25 miles, the P0740 code reappears. I clear the code at home, but it returns under similar conditions—this has occurred over three days of testing. My next step is to replace the Throttle Position Sensor (TPS), as well as both input and output speed sensors. I'm wondering if there are any other potential causes or diagnostic steps that might resolve this issue. Any insights or experiences with P0740 on 2004 Grand Cherokee models would be greatly appreciated. Thanks, Dean

Related fault codes

P0740

Comments (4)

Anonymous 2016-02-29 15:16

P0740 - Torque Converter Clutch (TCC) Control Circuit malfunction. Always begin with basic checks: verify fuses, ensure the brake switch is functioning properly (not just brake lights), and confirm that cruise control operates correctly. Use a professional OBD2 scanner to check for additional codes—especially in the P177x series—which may indicate deeper transmission issues. Note: Jeep transmissions are sensitive to fluid type; only use ATF+4 transmission fluid.

Anonymous 2016-03-01 00:36

The P0740 code indicates a fault in the Torque Converter Clutch control circuit, which directly prevents overdrive engagement. Common causes include: - Faulty torque converter lockup solenoid - Defective engine coolant temperature sensor - Damaged torque converter clutch - Valve body malfunction - Contaminated or dirty transmission fluid restricting hydraulic flow A common misdiagnosis is attributing the issue to engine misfires, internal transmission failure, or driveline problems. I recommend starting with a complete transmission fluid and filter change as a first step. This often resolves minor contamination issues and may restore proper operation.

Anonymous 2016-06-13 17:04

Hi kev2 — I'm experiencing the same P0740 code on my 2010 Jeep Wrangler, and now cruise control isn't working either. Could you clarify how this specific code relates to cruise control? My vehicle has been in and out of repair shops for months; it just came back Friday with the check engine light on while driving up a bridge. This is the only code showing on my basic OBD2 reader. Any insight would be helpful — thanks!

Anonymous 2016-06-14 13:24

It's worth checking if the brake light switch is malfunctioning. This sensor isn't just for brake lights—it also provides critical input to cruise control and torque converter clutch (TCC) engagement. A faulty signal can trigger P0740 and prevent overdrive operation.