DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0340

DTC P0340 : CMP Sensor A No Signal

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS.

-3. Start the engine.

-4. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0335 indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at CMP sensor A and the ECM.

2. Open wire check (IG1(CAM) line):

Open wire check (IG1(CAM) line)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there battery voltage?
-YES- The IG1(CAM) wire is OK. Go to step 3.
-NO- Repair an open in the IG1(CAM) wire between No. B7 fuse in the under-dash fuse/relay box and CMP sensor A, then do the repair verification.

3. Determine possible failure area (CAM line, others):

Determine possible failure area (CAM line, others)
-1. Measure the voltage between test points 1 and 2.









Is there about 5.0 V?
-YES- The CAM wire is OK. Go to step 4.
-NO- There is a problem in the CAM wire. Go to step 5.

4. Open wire check (LG2 line):

Open wire check (LG2 line)
-1. Measure the voltage between test points 1 and 2.









Is there battery voltage?
-YES- The LG2 wire is OK. Replace CMP sensor A CMP Sensor A Removal and Installation, then do the repair verification.
-NO- Repair an open in the LG2 wire between CMP sensor A and G101, then do the repair verification.

5. Shorted wire check (CAM line):

Shorted wire check (CAM line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the CAM wire between the ECM (C16) and CMP sensor A, then do the repair verification.
-NO- The CAM wire is not shorted. Go to step 6.

6. Open wire check (CAM line):

Open wire check (CAM line)
-1. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The CAM wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.
-NO- Repair an open in the CAM wire between the ECM (C16) and CMP sensor A, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM idle learn procedure ECM/PCM Idle Learn Procedure.

-6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0340 indicated?
-YES- Check for poor connections or loose terminals at CMP sensor A and the ECM. If the ECM was updated, substitute a known-good ECM Service and Repair, then recheck. If the ECM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the ECM was substituted, replace the original ECM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.