Saab P1300: Bank 1 Ignition Low Side Short
The P1300 code is a Saab-specific diagnostic trouble code indicating multiple low side shorts detected in Bank 1 ignition or coil control circuits. This means the engine control module (ECM) has detected a short-to-ground condition on the low-tension side of the ignition coil driver circuits. The low side refers to the ground control side of the ignition transistor, which can be caused by a faulty ignition cassette (direct ignition module), damaged wiring, or an internally shorted coil.
01. Most Common Causes
- Faulty direct ignition cassette (ignition module)
- Short to ground in the coil control circuit wiring
- Internally shorted ignition coil (leakage to ground)
- Corroded or moisture-contaminated coil connectors
- Internal ECM failure in the ignition driver circuit
- Abnormal resistance in the ignition system ground return circuit
02. Symptoms You Will Notice
- Engine misfire or rough running
- Check Engine Light illuminated
- Reduced engine power or stalling
- Hard starting or no start condition
03. Step-by-Step Diagnosis
Scan for codes and verify P1300 is present; check for additional codes.
Inspect ignition cassette and coil connectors for corrosion, moisture, or damage.
Test ignition coil primary and secondary resistance with a multimeter.
Check for short to ground on the low side control circuit at the ECM connector.
Swap ignition cassette with a known good unit if possible to isolate the fault.
If all else fails, test ECM ignition driver output with a lab scope or replace ECM.
1. Frequently Asked Questions
Is it safe to drive?▼
No, driving with P1300 is not recommended. The short circuit can cause further damage to the ECM or ignition system, and the engine may misfire or stall unexpectedly, creating a safety hazard.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on the root cause. A new ignition cassette can cost $150-$400, plus labor. ECM replacement can exceed $1000.