Air Suspension Control Module (ASCM)

C2129-16-BATTERY VOLTAGE - CIRCUIT VOLTAGE BELOW THRESHOLD

For a complete wiring diagram, refer to the Wiring Information.





- When Monitored:
Ignition on. Battery voltage between 9 and 16 volts.

- Set Condition:
The Air Suspension Control Module (ASCM) detects the battery voltage has dropped below 10 Volts for more than 15 seconds.





Diagnostic Test

1. CHARGING SYSTEM DTCS PRESENT
1. Ignition on, engine not running.
2. With the scan tool, read DTCs in the Powertrain Control Module (PCM).

Are there any Charging System or related voltage DTCs present?

Yes

- Perform the appropriate Charging System DTC diagnostic procedures before continuing with this test. A L L Diagnostic Trouble Codes ( DTC ).

No

- Go To 2

2. DTC IS ACTIVE
1. With the scan tool, record and erase DTCs.
2. With the scan tool, read the DTCs in the ASCM.

Is the DTC status Active at this time?

Yes

- Go To 3

No

- Go To 5

3. (A206) FUSED B(+) CIRCUIT OPEN OR HIGH RESISTANCE




1. Disconnect the ASCM C2 harness connector.
2. Ignition on, engine not running.
3. With a 12-volt test light connected to ground, check the (A206) Fused B+ circuit in the ASCM C2 harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 4

No

- Repair the (A206) Fused B(+) circuit for an open circuit or high resistance.
- Perform the ASCM VERIFICATION TEST. ASCM Verification Test.

4. (Z916) GROUND CIRCUIT OPEN OR HIGH RESISTANCE




1. Turn the ignition off to the lock position
2. With a 12-volt test light connected to B+, check the (Z916) Ground circuit in the ASCM C2 harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Replace the Air Suspension Control Module (ASCM). Air Suspension Control Module - Removal.
- Perform the ASCM VERIFICATION TEST. ASCM Verification Test.

No

- Repair the (Z916) Ground circuit for an open circuit or high resistance.
- Perform the ASCM VERIFICATION TEST. ASCM Verification Test.

5. INTERMITTENT WIRING AND CONNECTORS
1. Using the wiring diagram/schematic as a guide, inspect the wiring harness and connectors.
2. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
3. Look for the data to change or for the DTC to reset during the wiggle test.
4. While monitoring the scan tool data relative to this circuit, move the selector switch to each position several times.
5. Look for the data to change other than as expected or for the DTC to reset.

Were any problems found?

Yes

- Repair as necessary.
- Perform the ASCM VERIFICATION TEST. ASCM Verification Test.

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time.