A Problem In Mainshaft Speed Sensor Circuit

DTC P0715: A Problem in Mainshaft Speed Sensor Circuit

NOTE: Record all freeze data and review General Troubleshooting Information before you troubleshoot.

Code P0715 (15) doesn't always mean there's an electrical problem in the mainshaft or countershaft speed sensor circuit; code P0715 (15) may also indicate a mechanical problem in the transmission. Any problem causing irregular countershaft-to-mainshaft speed difference can cause this code.
1. Turn the ignition switch ON (II).
2. Check whether the OBD II scan tool indicates the code for the throttle position (TP) sensor or the engine coolant temperature (ECT) sensor.
Does the OBD II scan tool indicate the code for the TP sensor or the ECT sensor?
YES - Perform the troubleshooting flowchart for the TP sensor or the ECT sensor. Recheck for code P0715 after troubleshooting.
NO - Go to step 3.
3. Turn the ignition switch OFF.
4. Disconnect the mainshaft speed sensor connector.
5. Turn the ignition switch ON (II).





6. Measure the voltage between the No. 1 terminal of the mainshaft speed sensor connector and body around.
Is there about 5 V ?
YES - Go to step 7.
NO - Go to step 15.
7. Turn the ignition switch OFF.
8. Disconnect the PCM connector D (16P).





9. Check for continuity between the No. 2 terminal of the mainshaft speed sensor connector and body ground.
Is there continuity?
YES - Repair short to ground in the wire between PCM connector terminal D11 and the mainshaft speed sensor connector.
NO - Go to step 10.
10. Reconnect the PCM connector D (16P).





11. Check for continuity between the No. 3 terminal of the mainshaft speed sensor connector and body ground.
Is there continuity?
YES - Go to step 12.
NO - Repair open in the wire between PCM connector terminal D12 end the mainshaft speed sensor.
12. Turn the ignition switch ON (II).





13. Measure the voltage between the No. 2 and No. 3 terminals of the mainshaft speed sensor connector.
Is there about 5 V?
YES - Go to step 19.
NO - Go to step 14.





14. Measure the voltage between PCM connector terminals D11 and D12.
Is there about 5 V ?
YES - Repair open in the wire between PCM connector terminal D11 and the mainshaft speed sensor.
NO - Check for loose terminal fit in the PCM connectors D11, D12 and C28. If necessary, substitute a known-good PCM and recheck.





15. Measure the voltage between PCM connector terminal C28 and body ground.
Is there 4.75 - 5.25 V ?
YES - Repair open in the wire between PCM connector terminal C28 and the mainshaft speed sensor.
NO - Go to step 16.
16. Turn the ignition switch OFF.
17. Disconnect PCM connector C (31P).





18. Check for continuity between PCM connector terminal C28 and body ground.
Is there continuity?
YES - Repair short to ground in the wire between PCM connector terminal C28 and the mainshaft speed sensor.
NO - Check for loose terminal fit in the PCM connectors D11, D12 and C28. If necessary, substitute a known-good PCM and recheck.
19. Connect the mainshaft speed sensor connector.





20. Measure the voltage between PCM connector terminals D11 and D12.
Is there about 5 V or 0 V ?
YES - Go to step 21.
NO - Replace the mainshaft speed sensor.
21. Start the engine, and run it at idle in the P position.





22. Hold the engine at idle, and measure the voltage between PCM connector terminals D11 and D12.
Is there 1.5 - 3.5 V?
YES - Check for loose terminal fit in the PCM connectors D11, D12 and C28. If necessary, substitute a known-good PCM and recheck.
NO - Replace the mainshaft speed sensor.