P1764 GOVERNOR PRESSURE SENSOR VOLTS TOO LOW

NOTE: Perform TRANSMISSION VERIFICATION TEST VER-1 after repairs are complete.

NOTE: For harness connector terminal identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS . For component locations, see COMPONENT LOCATIONS .

Circuit Description

Circuit is monitored continuously while ignition is on and engine is running. DTC sets if governor pressure is
less than .1 volt for 8.5 seconds.

Possible Cause

The following items may be cause of concern:

• Governor pressure sensor harness defective.
• Governor pressure/temperature sensor defective.
• Governor pressure sensor signal shorted to sensor ground circuit.
• Governor pressure sensor signal circuit shorted to ground.
• Transmission harness/solenoid assembly defective.
• PCM defective.
• Solenoid pack connector 5-volt supply circuit open.
• Governor pressure sensor ground circuit open.
• Governor pressure sensor signal circuit shorted to voltage.
• Governor pressure sensor signal circuit open.

Diagnostic Procedure

1. Using scan tool, read DTCs. If good trip counter for DTC P1764 is not displayed or displayed count is not zero, go to step 12 . If good trip counter is displayed and displayed count is zero, go to next step.
2. Repair any other transmission-related DTCs before proceeding. See DIAGNOSTIC TROUBLE CODE DEFINITIONS under SELF-DIAGNOSTIC SYSTEM. If no other transmission-related DTCs exist, go to next step.
3. Turn ignition off. Record all DTCs and one trip failures. If DTC P1899 is present, repair P/N switch DTC first. See DTC P1899: P/N SWITCH STUCK IN PARK OR IN GEAR (DIESEL) or DTC P1899: P/N PERFORMANCE (GASOLINE) . If DTC P1899 is not present, go to next step.
4. Start engine and allow it to reach normal temperature. Check transmission fluid level and condition. Correct transmission fluid level or condition as necessary. See appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If transmission fluid level and condition are okay, go to next step.
5. Turn ignition off. Disconnect transmission solenoid assembly harness connector. Disconnect PCM harness connector C2 (White). Measure resistance of 5-volt supply circuit between transmission solenoid harness connector terminal No. 2 and PCM harness connector C2 (White) terminal No. 31. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair 5-volt supply circuit for open.
6. Measure resistance between ground and governor pressure sensor signal circuit at transmission solenoid harness connector terminal No. 4. If resistance is less than 5 ohms, repair governor pressure sensor signal circuit for short to ground. If resistance is 5 ohms or more, go to next step.
7. Disconnect PCM harness connector C1 (Black). Measure resistance between governor pressure sensor signal circuit and sensor ground circuit at transmission solenoid harness connector terminals No. 3 and 4. If resistance is less than 5 ohms, repair governor pressure sensor circuit for short to sensor ground circuit. If resistance is 5 ohms or more, go to next step.
8. Remove transmission oil pan. See appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. Disconnect governor pressure/temperature sensor harness connector. Measure resistance of 5-volt supply circuit between governor pressure/temperature sensor harness connector terminal "A" and transmission solenoid harness connector terminal No. 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS.
9. Measure resistance of governor pressure sensor signal circuit between ground and governor pressure/temperature sensor harness connector terminal "B". If resistance is less than 5 ohms, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is 5 ohms or more, go to next step.
10. Measure resistance between governor pressure sensor signal circuit and sensor ground circuit at governor pressure/temperature sensor harness connector terminals "B" and "D". If resistance is less than 5 ohms, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is 5 ohms or more, go to next step.
11. Using a DVOM, backprobe governor pressure sensor signal circuit at PCM harness connector C2 (White) terminal No. 29. Start and idle engine. Place gearshift lever in "N" position. Using scan tool, observe governor pressure sensor voltage. Compare scan tool value with DVOM voltage. If voltages match, replace governor pressure/temperature sensor. See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If voltages do not match, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE.
12. Conditions required to set DTC are currently not present. Inspect all applicable connectors and terminals for damage. Repair as necessary. If connectors and terminals are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.