P0840
DTC P0840: Problem in 2nd Clutch Pressure Switch CircuitNOTE: Record all freeze data before you troubleshoot.
1. Disconnect the 2nd clutch pressure switch.
2. Turn the ignition switch ON (II).
3. Measure the voltage between PCM connector terminal C13 and body ground.
Is there about 5 V?
YES - Go to step 4.
NO - Check for short to ground in the wire between PCM connector terminal C13 and the 2nd clutch pressure switch. If wire is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known good PCM, replace the original PCM.
4. Measure the voltage between the 2nd clutch pressure switch connector terminal and body ground.
Is there about 5 V?
YES - Go to step 5.
NO - Repair open in the wire between PCM connector terminal C13 and the 2nd clutch pressure switch.
5. Turn the ignition switch OFF.
6. Measure the resistance between the 2nd clutch pressure switch connector terminal and body ground.
Is there 40 M ohms or more?
NOTE: An open circuit is greater than 40 M ohms
YES - Go to step 7.
NO - Replace the 2nd clutch pressure switches
7. Connect the 2nd clutch pressure switch connector.
8. Raise the front of the vehicle, make sure it is securely supported, and allow the front wheels to rotate freely.
9. Start the engine, and shift into M position.
10. Drive the vehicle in 2nd gear for more than five seconds.
11. While driving in 2nd gear, measure the voltage between PCM connector terminal C13 and body ground.
Is there 0 V?
YES - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Check 2nd clutch pressure. If pressure is in specification, replace the 2nd clutch pressure switch.