Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B153A 00: Liftgate Latch Switch Signal CircuitDTC B153A 08: Liftgate Latch Switch Signal Circuit Signal Invalid
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Liftgate Module B+ | B153A 08, B396A 02 | B153A 08, B396A 02 | -- | -- |
Liftgate Module B+ | U0230 00 | U0230 00 | -- | -- |
Liftgate Position Sensor 5V Reference Voltage | B153E 02 | B153B 08 | 2 | B1019 00 |
Full Open Signal | B153E 08 | B153B 05 | 2 | -- |
Object Sensors Signal | B153F 02 | B153F 05 | B153F 05 | B153F 03, B153F 07 |
Open/Close Switches Signal | B2494 02 | 1, 2 | 1, 2 | -- |
Pawl Switch Signal | B153A 00 | B153A 08 | B153A 00 | B153A 08 |
Position Sensor Signal 1 | B153E 08 | B153E 08 | B153E 05 | -- |
Position Sensor Signal 2 | B153E 08 | B153A 08 | B153E 05 | B153E 08 |
Ratchet Switch Signal | B153A 00 | B153A 08 | B153A 00 | B153A 08 |
Sector Switch Signal | B153A 00 | B153A 00 | B153A 00 | B153A 08 |
Disengage Clutch Control | B396B 02 | B396B 04 | B396B 01 | -- |
Engage Clutch Control | B396B 02 | B396B 04 | B396B 01 | -- |
Liftgate Latch Cinch Control | B2495 02 | B2495 04 | B2495 01 | -- |
Liftgate Latch Release Control | B2495 02 | B2495 04 | B2495 01 | -- |
Liftgate Motor Close Control | B396A 02 | B396A 04 | B396A 01 | B153E 08 |
Liftgate Motor Open Control | B396A 02 | B396A 04 | B396A 01 | B153E 08 |
Full Open Low Reference | -- | B153B 05 | 2 | -- |
Liftgate Switches Low Reference | -- | B153A 08 | 1 | B153E 08 |
Position Sensor Low Reference | -- | B0153E 08 | 2 | -- |
Liftgate Control Module Ground | -- | U0230 00 | 2 | -- |
1. Liftgate Switch Malfunction 2. Liftgate Malfunction | ||||
Circuit/System Description
The ratchet, pawl, and sector switches are part of the liftgate latch assembly and are used by the liftgate module (LGM) to determine the state of the latch during the process of latching or unlatching. The ratchet and pawl switches will be inactive when the primary and secondary latches are latched, and the sector switch will be active during the power cinch function. Each of the latch switch signal circuits are supplied battery voltage through a resistor and monitored within the LGM. The latch switches share a common low reference circuit from the LGM and when the switch contacts close the signal circuit goes low and the LGM determines the switch to be active. The full open switch is a limit switch mounted on the gear motor assembly alongside the swing arm gear. The full open switch signal circuit is supplied battery voltage through a resistor and monitored within the LGM. When the liftgate reaches the full open position, the switch signal circuit is closed to the low reference circuit and the signal circuit voltage goes low.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B153A 00
The LGM detects a fault in any of the following switch signal circuits:
| • | Ratchet switch |
| • | Pawl switch |
| • | Sector switch |
B153A 08
When the LGM detects a loss of B+ voltage, an open/high resistance in the sensor signal circuit, an open/high resistance in the liftgate latch low reference circuit, or any incorrect combination of signals from the following switch inputs:
| • | Ratchet switch |
| • | Pawl switch |
| • | Sector switch |
Action Taken When the DTC Sets
| • | Power open will be disabled. |
| • | The latch may be inoperative or not function normally. |
Conditions for Clearing the DTC
| • | The DTC will be current for as long as the fault is present. |
| • | When the fault is no longer present, the DTC will be a history DTC. |
| • | A history DTC will clear after 50 ignition cycles. |
Diagnostic Aids
DTC B153A may be set when the vehicle is driven while the liftgate is open, as when the owner transports a large package in the rear of the vehicle. The DTC will become history after the liftgate is closed and does not affect normal liftgate operation.
Note: Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the appropriate procedure.
Whenever the LGM loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the LGM.
Reference Information
Schematic Reference
Connector End View Reference
Vehicle Access Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
- Ignition ON, observe the scan tool LGM Latch Sector Sw parameter while commanding the liftgate OPEN by using the liftgate outside handle. The parameter should change from Inactive to Active to Inactive during the OPEN command.
- Observe the scan tool LGM Latch Pawl Sw. and LGM Latch Ratchet Sw. parameters while commanding the liftgate OPEN by using the liftgate outside handle, the parameters should change from Inactive to Active during the OPEN command.
Circuit/System Testing
- Ignition OFF, disconnect the C2 harness connector at the LGM.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
- Ignition OFF, connect the C2 harness connector at the LGM and disconnect the harness connector at the liftgate latch.
- Test for less than 10 ohms between the low reference circuit terminal 2 and ground.
- Ignition ON, verify the scan tool LGM Latch Pawl Sw. parameter is Inactive.
- Verify the scan tool LGM Latch Ratchet Sw. parameter is Inactive.
- Verify the scan tool LGM Latch Sector Sw. parameter is Inactive.
- Install a 3A fused jumper wire between the signal circuit terminal 5 and low reference circuit terminal 2. Verify the scan tool LGM Latch Pawl Sw. parameter is Active.
- Install a 3A fused jumper wire between the signal circuit terminal 6 and low reference circuit terminal 2. Verify the scan tool LGM Latch Ratchet Sw. parameter is Active.
- Install a 3A fused jumper wire between the signal circuit terminal 4 and low reference circuit terminal 2. Verify the scan tool LGM Latch Sector Sw. parameter is Active.
- If all circuits test normal, test or replace the liftgate latch.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the LGM. |
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM. |
| ⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for LGM replacement, setup, and programming |
