TH - Reverse Switch (RS)

TH: REVERSE SWITCH (RS)

TH - DTC P0812 Check RS Switch Function

NOTE: During KOEO Self-Test, gearshift lever in NEUTRAL.

Key on, engine off.

Access RS PID and observe PID cycling ON/OFF with gear shift lever in and out of REVERSE.

Does reading change from ON to OFF?

YES KEY OFF. Fault intermittent. DISCONNECT PCM. INSPECT both ends of the connector for damaged or pushed out pins, corrosion, loose wires. REPAIR as necessary. If OK, REPLACE PCM.

NO KEY OFF. GO to TH2.

TH2 - Check RS Switch Resistance

Locate the reverse switch (RS) near the transmission shift linkage.

Inspect switch and bracket for damage, bent or broken conditions. Repair as required.

Disconnect RS harness connector.

Measure the resistance between the reverse switch terminals with the shift lever in reverse.

Is the resistance less than 5.0 ohms?

YES GO to TH3.

NO REPLACE the RS switch.

TH3 - Check RS Circuit For Open In Harness

Disconnect scan tool.

Disconnect PCM.

Measure resistance of the RS circuit between PCM harness connector pin and RS harness connector.

Where applicable, measure resistance of the SIG RTN circuit between PCM harness connector pin and RS harness connector.

Are both resistances less than 5.0 ohms?

YES GO to TH4.

NO REPAIR open circuit.

TH4 - Check RS Circuit For Short To SIG RTN Or Chassis Ground In Harness

Measure resistance between RS and SIG RTN circuits at the PCM harness connector.

Measure resistance between RS circuit at the PCM harness connector and chassis ground.

Are both resistances greater than 10,000 ohms?

YES REPLACE PCM.

NO REPAIR short circuit.