P1530

DTC P1530 Ignition Timing Adjustment Switch Circuit:

Ignition Timing Circuit:

CIRCUIT DESCRIPTION

The test switch terminal is located in the duty check data link connector. When the test switch terminal is grounded the ECM fixes the Ignition timing to base timing.


CONDITIONS FOR SETTING THE DTC


- Test switch on.

- Vehicle speed greater than 32 km/h (20 mph).

- Continuous for 5 seconds


ACTION TAKEN WHEN THE DTC SETS


- The Malfunction Indicator Lamp (MIL) will illuminate.

- The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.


CONDITIONS FOR CLEARING THE MIL/DTC

- The MIL will turn "OFF" after three consecutive drive cycles without a fault present.

- A DTC will clear after 40 consecutive warm-up cycles without a fault.

- DTC(s) can be cleared by using a scan tool or by disconnecting the ECM battery feed.

DIAGNOSTIC AIDS

Check for the following conditions:


- Poor connection or damaged harness. Inspect the wiring harness for damage.

If DTC P1530 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was last set. This may assist in determining how often the DTC sets.

If any wiring repairs need to be made, Refer to Repair Procedures in Diagrams.

TEST DESCRIPTION


Number(s) below refer to the step number(s) on the Diagnostic Table.


1. The Engine OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool it applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. Determines if fault is present. Review Freeze Frame data to determine when the DTC set. Always record this information.

3. Checks for a short to ground on the test switch terminal and its circuitry. In this state Ignition timing will be fixed at its base timing specification.