P0958

P0958-AUTOSTICK CIRCUIT HIGH (ERS)





For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


The AutoStick(R) (ERS) Tow/Haul Overdrive Off switch uses a MUX (multiplex) switch. ERS is an electronic gear selector that will upshift and downshift through all gears but only up to the selected gear. When compared to the AutoStick(R) feature, AutoStick(R) will only stay in the selected gear.

The Powertrain Control Module (PCM) monitors the AutoStick(R) (ERS) Tow/Haul Signal circuit for voltage changes in respect to the position of the switch. If the PCM detects an improper voltage during upshift, downshift, or in its natural state, a DTC will set.


- When Monitored:
Whenever the engine is running.

- Set Condition:
The PCM detects a voltage above 4.75 volts for the period of 5.0 seconds on the AutoStick(R) (ERS) Tow/Haul Signal circuit.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 68RFE - Pre-Diagnostic Troubleshooting Procedure


Diagnostic Test


1. CHECK IF THE DTC IS CURRENT
With the scan tool, read DTCs.
Is the status Active or is the Starts Since Set counter 0 for this DTC?

Yes


- Go to2


No


- Go to7



2. CHECK THE (T5) AUTOSTICK(R) (ERS) TOW/HAUL SIGNAL CIRCUIT
Turn the ignition off to the lock position.
Ignition on, engine running.
With the scan tool, read the AutoStick (ERS) voltage.
Is the voltage above 4.75 volts?

Yes


- Go to3


No


- Go to6



3. (T5) AUTOSTICK(R) (ERS) TOW/HAUL SIGNAL CIRCUIT SHORT TO VOLTAGE




Turn the ignition off to the lock position.
Disconnect the PCM C1 harness connector.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Ignition on, engine not running.
Measure the voltage of the (T5) AutoStick(R) (ERS) Tow/Haul Signal circuit at the appropriate terminal of Miller tool #8815.
Is the resistance above 0.5 volts?

Yes


- Repair the (T5) AutoStick(R) (ERS) Tow/Haul Signal circuit for a short to voltage.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Go to4



4. CHECK THE (T5) AUTOSTICK(R) (ERS) TOW/HAUL SIGNAL CIRCUIT FOR AN OPEN




Turn the ignition off to the lock position.
Disconnect the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch harness connector.
Measure the resistance of the (T5) AutoStick(R) (ERS) Tow/Haul Signal circuit between of the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch harness connector and the appropriate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?

Yes


- Repair the (T5) AutoStick(R) (ERS) Tow/Haul Signal circuit for an open.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Go to5



5. CHECK THE (T160) SENSOR GROUND CIRCUIT FOR AN OPEN




Measure the resistance of the (T160) Sensor Ground circuit between of the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch harness connector and the appropriate terminal of Miller tool #8815.
Is the resistance above 5.0 ohms?

Yes


- Repair the (T160) Sensor Ground circuit for an open.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Go to6



6. CHECK THE AUTOSTICK(R) (ERS) TOW/HAUL OVERDRIVE OFF SWITCH









Measure the resistance of the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch between the AutoStick(R) (ERS) Signal circuit and the Sensor Ground circuit in all four shift positions. Use the above chart to verify your findings.
Are the resistances of the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch within limits?

Yes


- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply. If no problems are found, replace and program the PCM. With the scan tool, perform Quick Learn.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Replace the AutoStick(R) (ERS) Tow/Haul Overdrive Off Switch.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test



7. CHECK THE WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.

NOTE: It may be necessary to test drive the vehicle to enable or cause the DTC to set.

Check for any Service bulletins that may apply.
Were there any problems found?

Yes


- Repair as necessary.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Test Complete.