GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC P42 Commercial Chassis 🢒 DTC 🢒 DTC 52 System Voltage High Long

Object Number: 230184 Size: MF
Automatic Transmission Components Gasoline
Handling ESD Sensitive Parts Notice

Circuit Description

Ignition voltage is supplied to the Transmission Control Module (TCM) to indicate the ignition status of the ignition switch. Battery voltage is supplied to the TCM to maintain memory of learned functions and parameters.

If the TCM detects a high ignition voltage for a long time, then DTC 52 sets.

Conditions for Setting the DTC
    • The ignition is ON.
    • The ignition system voltage is greater than 16 volts.
    • All conditions are met for 27 minutes.

Action Taken When the DTC Sets
    • The TCM commands maximum line pressure.
    • The TCM commands 2nd gear.
    • The TCM inhibits TCC.
    • DTC 52 is stored in TCM history.

Conditions for Clearing the DTC
    • The TCM clears the DTC from Current to History when the fault condition(s) no longer exist and the ignition switch is cycled OFF and then ON.
    • A scan tool can clear the DTC from Current and History status. The TCM clears the DTC from the TCM history if the vehicle completes 40 ignition cycles without a failure reported.
    • The TCM cancels the DTC default actions when the fault no longer exists and the ignition is cycled OFF and then ON.

Diagnostic Aids
    • Charging the battery and jump-starting an engine may set DTC 52. If DTC sets when an accessory is operated, check for faulty connections or excessive current draw. Refer to the appropriate service manual for circuit details.
    • Check for faulty connections at the starter solenoid, fusible link, or battery cable connections.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Normal battery voltage is between 12-15 volts.

  2. This determines if the Scan Tool is reading a non-actual system voltage from a faulty TCM.

DTC 52

Step

Action

Value(s)

Yes

No

1

Were you sent here from the "Powertrain On-Board Diagnostic (OBD) System Check?"

--

Go to Step 2

Go to On-Board Diagnostic System Check

2

  1. Start the vehicle.
  2. Increase the engine speed to above 1200 RPM.
  3. Using the J 39200 DMM, measure the voltage across the battery terminals.

Is the voltage greater than the specified voltage?

16 V

Go to Charging System Diagnosis

Go to Step 3

3

  1. Install the Scan Tool .
  2. Start the vehicle.

    3. Important:: Before clearing the DTC's, record the Current and History DTC's information for reference. The Clear Info function erases the stored Current and History DTC from the TCM.

  3. Record Current and History DTC's, then clear the DTC.
  4. Increase engine speed to above 1200 RPM.
  5. Observe Ignition Voltage on the Scan Tool .

Is the voltage greater than the specified voltage?

16 V

Go to Step 4

Go to Diagnostic Aids

4

Replace TCM. Refer to DTC 51 PROM Error TCM Replacement.

Is the replacement complete?

--

Go to Step 5

--

5
  1. After the repair is complete, select "DTC," then "Clear Info."
  2. Operate the vehicle for at least 2 minutes with the engine speed more than 1200 RPM.
  3. Observe Ignition Voltage on the Scan Tool .

Is the Ignition Voltage below the specified value for the full 2 minutes?

16 V

System OK

Begin Diagnosis again.

Go to Step 1