Pinpoint Tests AA: DTC C1948
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests
Pinpoint Test AA: DTC C1948
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Lamp Fault Codes (LFCs)
The following Lamp Fault Code (LFC) indicates the specific fault associated with DTC C1948:
- LFC 7-7 - Front Driver's Seat Track Position Switch Circuit Resistance Out of Range
Normal Operation
The seat track position sensor informs the Restraints Control Module (RCM) of the driver seat position.
The RCM monitors the driver seat track position sensor circuits. If the RCM detects a current out of range condition, it will store DTC C1948 in memory, flash a LFC 7-7 on the air bag warning indicator.
- DTC C1948 (Front Driver's Seat Track Position Switch Circuit Resistance Out of Range) - If the RCM detects a current out of range between forward and rearward on the driver seat track position switch, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Driver seat track position sensor
- RCM
PINPOINT TEST AA: DTC C1948
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.
NOTICE: Use the correct probe adapter(s) when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.
NOTE: SRS components should only be disconnected or reconnected when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.
NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the Pinpoint Test. Inspection and Verification
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AA1 RETRIEVE SRS DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC C1948 retrieved on-demand during self-test?
Yes
The fault condition is still present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self test. GO to AA2.
No
This is an intermittent fault when present as a CMDTC only (DTC not retrieved on demand). The fault condition is not present at this time.
GO to AA3.
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AA2 CHECK THE SEAT TRACK POSITION SENSOR
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Install a known good driver seat track position sensor. Refer to Seat Position Sensor Service and Repair.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC C1948 retrieved on-demand during self-test?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AA4.
No
CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. REPAIR any intermittent wiring, terminals or connector concerns found. GO to AA4.
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AA3 CHECK FOR AN INTERMITTENT FAULT
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC C1948 retrieved on-demand during self-test?
Yes
The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self test. GO to AA2.
No
CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. REPAIR any intermittent wiring, terminals or connector concerns found. GO to AA4.
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AA4 CHECK FOR ADDITIONAL SRS DTCs
- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Reconnect all SRS components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Are any DTCs retrieved on-demand during self-test?
Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the Supplemental Restraint System (SRS) DTC Chart for pinpoint test direction. Supplemental Restraint System (SRS) DTC Chart
No
CLEAR all CMDTCs. PROVE OUT the SRS. REPAIR is complete. RETURN the vehicle to the customer.
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