P1662 - IDM EN Circuit Failure
The P1662 code indicates a failure in the Injector Driver Module (IDM) Enable circuit. The IDM is responsible for controlling the fuel injectors in diesel engines, and the enable circuit provides power to the module. When this circuit fails, the IDM may not receive power, causing the injectors to malfunction or not fire at all. This can lead to engine misfires, rough running, and potential stalling.
1. Symptoms You Will Notice
- Engine misfire or rough idle
- Hard starting or no start
- Check Engine Light illuminated
- Reduced engine power
2. Most Common Causes
- Faulty or internally failed electric power steering (EPS) control module
- Open circuit, short to ground, or short to voltage in the EPS output circuit wiring
- Corroded, bent, or poorly contacting connectors in the power steering system harness
- Failed data communication signal between the EPS module and the PCM/ECM
- Power supply or ground issues to the power steering control module
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the P1662 code and check for related codes.
Step 2: Inspect the IDM relay and fuse; test for power at the relay.
Step 3: Check wiring and connectors between the PCM and IDM for damage or corrosion.
Step 4: Test the IDM enable circuit voltage with a multimeter; should be battery voltage with key on.
Step 5: If circuit is intact, test the IDM module itself or replace it.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The engine may stall or lose power unexpectedly, posing a safety risk. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost ranges from $150 to $400, depending on whether the issue is a relay, wiring repair, or IDM replacement.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.