P1345 Injector Driver Module Fault
The powertrain control module (PCM) has detected that the injector driver module (IDM) has stored internal fault codes. The IDM is responsible for supplying the high voltage and current needed to fire the diesel injectors, common on 7.3L Power Stroke engines. This code indicates a failure in the injection control circuit, such as a short, open, or injector coil failure, or an internal IDM fault.
01. Most Common Causes
- Faulty injector driver module (IDM) – often due to overheating or water intrusion
- Damaged, burned, or disconnected under-valve-cover harness (UVCH)
- Injector(s) with shorted or open coil
- Loose, corroded, or backed-out pins at IDM or PCM connectors
- Low battery voltage or fault in IDM power circuit (fuse, relay)
02. Symptoms You Will Notice
- Engine misfire or rough idle
- Loss of power or hesitation under load
- Check Engine Light illuminated
- Hard starting or no start
03. Step-by-Step Diagnosis
Scan for additional codes in both PCM and IDM
Inspect UVCH for damage, burns, or loose connections
Test injector coil resistance with a multimeter
Check IDM power supply voltage and ground circuits
Perform IDM self-test or swap with known-good unit if available
1. Frequently Asked Questions
Is it safe to drive?▼
No, driving with this code can cause further damage to the IDM or injectors, and may leave you stranded. It is best to diagnose and repair immediately.
How much does it cost to fix?▼
Repair costs vary widely: a new IDM can cost $200–$600, plus labor. Harness repairs or injector replacement can add $100–$500 per injector. Total cost typically ranges from $300 to $1,500.