P053

Circuit Description

If the PCM does not receive 4X reference pulses from the Ignition Control Module for more than 0.4 second while the engine is running, Code P053 is set.

Test Condition(s)

1 Codes P019 and P035 are not set.
2. Engine speed greater than 568 rpm.

Failure Condition(s)

No 4X reference pulse has been received by the PCM for 0.4 second.

Action Taken

Code sets, no service telltale or message.

Notes on Fault Tree

1. Check to see if Code P035 is set, because a REF LO problem can cause other ignition problems.
2. Checking for power to the ignition control module.
3. Checking ignition control module ability to produce 4X reference pulses. If the system is operating correctly, you will measure 30 Hz or greater.
4. Open at fuse block. Check terminal contact.
5. Checking for open or short to ground on CKT 430.

Notes on Intermittents

This code may set due to a false start condition in which engine rpm exceeds 568 but does not start.