The Electronic Brake and Traction Control Module (EBTCM) controls the PWM signal on the traction control desired torque circuit while monitoring the wheel speed sensors to detect slippage. The PCM monitors the PWM signal and reduces engine torque as needed by retarding ignition timing, decreasing boost duty cycle, increasing air/fuel ratio, or, in severe cases, shutting OFF up to three fuel injectors. The PCM sends a PWM signal to the Electronic Brake and Traction Control Module (EBTCM) on the traction control delivered torque circuit informing the EBTCM of response made to the traction control desired torque signal. A problem with the traction control delivered torque circuit should cause DTC P1653 to set and traction control to be disabled. Refer to ABS/TCS for further information.
• | The ignition is ON. |
• | An improper voltage level has been detected on the traction control delivered torque control circuit. |
• | The above conditions present for at least 30 seconds. |
• | The PCM will not illuminate the malfunction indicator lamp (MIL). |
• | The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data. |
• | A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
• | The DTC can be cleared by using the scan tool Clear Info function. |
Check for the following conditions:
• | Poor connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
• | Damaged harness. Inspect the wiring harness for damage. |
• | If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a digital multimeter connected between the Traction Control Delivered Torque control circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the EBTCM. A change in voltage will indicate the location of the malfunction. |
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Number(s) below refer to the step number(s) on the Diagnostic Table.
Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.
Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.
Checks for a short to voltage on the control circuit.
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
Is voltage near the specified value? | B+ | |||||||||
Does the current reading remain between the specified values? | 0.001-0.5 Amp (1-500 mA) | |||||||||
Is voltage at the specified value? | 0 V | |||||||||
5 | Locate and repair short to voltage in the delivered torque control circuit. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |||||||
6 |
Is the fuse blown? | -- | ||||||||
7 |
Is action complete? | -- | -- | |||||||
8 |
Is voltage near the specified value? | B+ | ||||||||
9 |
Was a problem found? | -- | ||||||||
10 |
Was a problem found? | -- | ||||||||
11 |
Does the test light flash ON and OFF? | -- | Refer to Diagnostic Aids | |||||||
12 |
Was a problem found? | -- | ||||||||
13 | Locate and repair open in ignition feed circuit to the EBTCM. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |||||||
14 | Replace the EBTCM. Refer to On-Vehicle Service in ABS/TCS. Is action complete? | -- | -- | |||||||
Replace the PCM. Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||||||||
16 |
Does the scan tool indicate DTC P1653 failed this ignition? | -- | System OK |