Injector Drive Module Service Tips


Read Before Injector Drive Module Replacement or Troubleshooting

The Injector Drive Module (IDM), responds to commands from the PCM, steps up the vehicle 12V power to 115V, supplies the 115V to activate the injectors and monitors faults in the IDM and injector electrical circuits.

IDM codes can indicate a problem with the IDM and/or injector electrical circuits. IDM codes can also be set by problems elsewhere in the engine.

IDM codes are stored in one of the three tests:

• Key on engine off (KOEO).

• Continuous memory codes.

• Injector electrical buzz test.

The only way to clear IDM codes is to clear the continuous codes.

The use of an appropriate scan tool is required to properly diagnose IDM and injector related problems.

Basic Diagnostic Steps

When IDM diagnostic codes (DTC) are present follow the following steps:

1. Record all codes in the key on engine off test (KOEO) and injector electrical buzz test.

2. Record and then clear the continuous codes.

3. Run the KOEO and injector electrical buzz tests.

4. IDM codes that reappear are hard faults.

5. If no codes reappear then the fault is intermittent.

6. Troubleshoot the codes.

Service Tips for Injector Buzz Test and

Scan Tool Codes P1219, P1298 & P1316

Injector Buzz Test

If an injector makes no buzzing sound or a faint buzzing sound and no fault codes are present you have a mechanical injector problem. No buzzing and an IDM code indicate that you have a problem with the electrical circuit on that injector.

P1219 – Cylinder Identification Low

Code P1219 can lead you to replace the IDM or PCM. This code is usually caused by a failed cam position sensor. Certain PCM calibrations will not set a P0340 or P0344 cam position sensor code. If you have an intermittent problem, it is likely a bad cam position sensor.

P1316 – IDM Codes Detected

Code P1316 is a warning code stored in continuous memory telling you IDM codes are stored elsewhere in either the key on engine off (KOEO) or injector electrical buzz test. Run all three tests, KOEO, continuous memory codes and the injector electrical buzz test. Note the codes, then clear the codes and run the KOEO test to make sure the codes are cleared. Run the injector electrical buzz test and diagnose the codes produced by the test.

P1298 – IDM failure

Code P1298 is commonly set by low battery voltage. If the battery voltage during cranking drops below 10.5 volts the IDM relay will shut off. Connect a battery charger or jumper battery, verify battery voltage and rerun your tests. Perform all code retrieval tests with a scan tool. If any other codes are present, diagnose and repair these first. If the engine cranks good and only the P1298 code is present, perform troubleshooting for the glow plug system, check for voltage drop or PCM reset during cranking and other possible no start conditions. Finally clear the codes and then turn the key on and off three times, allowing 5 seconds in the on position. Recheck for codes, if P1298 reappears the likely cause is the IDM.