Test Description

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2: This step tests for a short to ground or an open condition in the PPL/WHT wire which supplies VSS signal voltage to the cruise control module.
3: This step tests for a short to ground in the PPL/WHT wire which supplies VSS signal voltage from the instrument cluster assembly to junction block 3

DTC 021

Step	Action	Yes	No
Schematic Reference: Cruise Control Schematics
1	Did you perform the Diagnostic System Check - Cruise Control ?	Go to Step 2	Go to Diagnostic System Check - Cruise Control
2	Turn OFF the ignition. Disconnect connector C3 on the left instrument panel junction block. Disconnect the cruise control module connector. Test the VSS vehicle speed input circuit between the connector C3 cavity 7 of the left instrument panel junction block and cavity 12 of the cruise control module for an open or ground condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 5	Go to Step 3
3	Inspect for poor connections at the harness connector of the cruise control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 5	Go to Step 4
4	Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you Complete the replacement?	Go to Step 5	-
5	Install a scan tool. Turn ON the ignition, with the engine OFF. Pull the cruise control switch to the CANCEL position and hold. While holding the cruise control switch to the CANCEL position, push the cruise control ON switch 5 times within 3 seconds. Check that the CRUISE indicator lamp flashes rapidly. This confirms that any flash codes have been cleared. Does the CRUISE indicator lamp flash the same trouble code?	Go to Step 2	-