P1102-VISCOUS/CABIN HEATER RELAY SHORT CIRCUIT
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on and the ECM Viscous/Cabin Heater Relay command on.
- Set Condition:
The ECM detects excessive current on the Viscous/Cabin Heater Relay Control circuit for 0.5 second.
| Possible Causes |
| INTERMITTENT CONDITION |
| ASD RELAY OUTPUT CIRCUIT OPEN |
| CABIN HEATER RELAY |
| CABIN HEATER RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE |
| CABIN HEATER RELAY CONTROL CIRCUIT SHORTED TO GROUND |
| CABIN HEATER RELAY CONTROL CIRCUIT OPEN |
| ENGINE CONTROL MODULE |
Diagnostic Test
1. CABIN HEATER RELAY CLICKINGNOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the scan tool, actuate the Viscous/Cabin Heater Relay.
Is the Cabin Heater Relay clicking?
Yes
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To2
2. ASD RELAY OUTPUT CIRCUIT OPEN
Turn the ignition off.
Disconnect the Cabin Heater Relay from the PDC.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the ASD Relay Output circuit at the Cabin Heater Relay connector in the PDC.
Does the test light illuminate brightly?
Yes
- Go To3
No
- Repair the ASD Relay Output circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
3. CABIN HEATER RELAY
Turn the ignition off.
Install a substitute relay in place of the Cabin Heater Relay.
Turn the ignition on.
With the scan tool, actuate the Viscous/Cabin Heater Relay for at least 20 seconds.
With the scan tool, read ECM DTCs.
Did this DTC set again?
Yes
- Go To4
No
- Replace the Cabin Heater Relay.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
4. CABIN HEATER RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Cabin Heater Relay.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector in the PDC.
Turn the ignition on.
Measure the voltage on the Cabin Heater Relay Control circuit.
Is the voltage above 1.0 volt?
Yes
- Repair the Cabin Heater Relay Control circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To5
5. CABIN HEATER RELAY CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Remove the jumper wire and install the ASD Relay.
Measure the resistance between ground and the Cabin Heater Relay Control circuit.
Is the resistance above 1000 ohms?
Yes
- Go To6
No
- Repair the Cabin Heater Relay Control circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
6. CABIN HEATER RELAY CONTROL CIRCUIT OPEN
Measure the resistance of the Cabin Heater Relay Control circuit.
Is the resistance below 10.0 ohms?
Yes
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Repair the Cabin Heater Relay Control circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).